Validate International Securities Identification Number
You are encouraged to solve this task according to the task description, using any language you may know.
An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded checksum is correct.
Demonstrate that your code passes the test-cases listed below.
The format of an ISIN is as follows:
For this task, you may assume that any 2-character alphabetic sequence is a valid country code.
The checksum can be validated as follows:
- Replace letters with digits, by converting each character from base 36 to base 10, e.g.
AU0000XVGZA3→1030000033311635103. - Perform the Luhn test on this base-10 number.
There is a separate task for this test: Luhn test of credit card numbers.
You don't have to replicate the implementation of this test here – you can just call the existing function from that task. (Add a comment stating if you did this.)
| ISIN | Validity | Comment |
|---|---|---|
| US0378331005 | valid | |
| US0373831005 | not valid | The transposition typo is caught by the checksum constraint. |
| U50378331005 | not valid | The substitution typo is caught by the format constraint. |
| US03378331005 | not valid | The duplication typo is caught by the format constraint. |
| AU0000XVGZA3 | valid | |
| AU0000VXGZA3 | valid | Unfortunately, not all transposition typos are caught by the checksum constraint. |
| FR0000988040 | valid |
(The comments are just informational. Your function should simply return a Boolean result. See #Perl_6 for a reference solution.)
Useful resources:
- Interactive online ISIN validator
- Wikipedia article: International Securities Identification Number
Related tasks:
360 Assembly
<lang 360asm>* Validate ISIN 08/03/2019 VALISIN CSECT
USING VALISIN,R13 base register
B 72(R15) skip savearea
DC 17F'0' savearea
SAVE (14,12) save previous context
ST R13,4(R15) link backward
ST R15,8(R13) link forward
LR R13,R15 set addressability
LA R7,1 j=1
DO WHILE=(C,R7,LE,=A(NN)) do j=1 to hbound(tt)
LR R1,R7 j
SLA R1,4 ~
LA R4,TT-16(R1) @tt(j)
MVC CC,0(R4) cc=tt(j)
MVC C,=CL28' ' c=' '
MVC R,=CL28' ' r=' '
MVI ERR,X'00' err=false
MVC LCC,=F'0' lcc=0
LA R1,L'CC i=length(cc)
LENTRIA LA R5,CC-1 @cc
AR R5,R1 +i
CLI 0(R5),C' ' if cc[i]=' '
BE LENTRIB then iterate loop
ST R1,LCC lcc=lentrim(cc)
B LENTRIC leave loop
LENTRIB BCT R1,LENTRIA i--; if i<>0 then loop LENTRIC L R4,LCC lcc
IF CH,R4,EQ,=H'12' THEN if lcc=12 then
MVC LC,=F'0' lc=0
MVC WW,=CL28' ' ww=
LA R10,WW @ww
LA R6,1 i=1
DO WHILE=(C,R6,LE,LCC) do i=1 to lcc
LA R4,CC-1 @cc
AR R4,R6 +i
MVC CI(1),0(R4) ci=substr(cc,i,1)
LA R2,BASE36 @base36
LA R3,L'BASE36 length(base36)
BAL R14,INDEX r0=index(base36,ci)
IF LTR,R0,NZ,R0 THEN if p<>0 then
LR R1,R0 ip
BCTR R1,0 -1
XDECO R1,XDEC str(ip-1)
MVC 0(2,R10),XDEC+10 ww=ww||str(p-1)
ELSE , else
MVI ERR,X'FF' err=true
ENDIF , endif
LA R10,2(R10) @ww+=2
LA R6,1(R6) i++
ENDDO , enddo i
MVC C,=CL28' ' c=
LA R8,WW @ww
LA R9,C @c
LA R10,0 length(c)
LA R6,1 i=1
DO WHILE=(C,R6,LE,=A(L'WW)) do i=1 to length(ww)
IF CLI,0(R8),NE,C' ' THEN if ww[i]<>' ' then
MVC 0(1,R9),0(R8) c=ww[i]
LA R9,1(R9) @c++
LA R10,1(R10) length(c)++
ENDIF , endif
LA R8,1(R8) @ww++
LA R6,1(R6) i++
ENDDO , enddo i
ST R10,LC lc=length(c)
LA R6,1 i=1
DO WHILE=(CH,R6,LE,=H'2') do i=1 to 2
LA R4,CC-1 @cc
AR R4,R6 +i
MVC CI(1),0(R4) ci=substr(cc,i,1)
LA R2,ALPHA @alpha
LA R3,L'ALPHA length(alpha)
BAL R14,INDEX r0=index(alpha,ci)
IF LTR,R0,Z,R0 THEN if index(alpha,ci)=0 then
MVI ERR,X'FF' err=true
ENDIF , endif
LA R6,1(R6) i++
ENDDO , enddo i
SR R8,R8 i1=0
SR R9,R9 i2=0
IF CLI,ERR,EQ,X'00' THEN if not err then
SR R0,R0 0
L R6,LC i=lc
MVC R,=CL28' ' r=
LA R10,C @c
LA R11,R-1 @r
A R11,LC @r=@r+length(strip((c))
DO WHILE=(CH,R6,GE,=H'1') do i=lc to 1 step -1
MVC 0(1,R11),0(R10) r[k]=c[i]
BCTR R11,0 @r--
LA R10,1(R10) @c++
BCTR R6,0 i--
ENDDO , enddo i
LA R6,1 i=1
DO WHILE=(C,R6,LE,LC) do i=1 to lc step 2
LA R4,R-1 @r
AR R4,R6 +i
MVC CI(1),0(R4) ci=substr(r,i,1)
MVC XDEC,=CL12' ' ~
MVC XDEC(L'CI),CI ci
XDECI R2,XDEC int(ci)
AR R8,R2 i1=i1+int(ci)
LA R6,2(R6) i+=2
ENDDO , enddo i
LA R6,2 i=2
DO WHILE=(C,R6,LE,LC) do i=2 to lc step 2
LA R4,R-1 @r
AR R4,R6 +i
MVC CI(1),0(R4) ci=substr(r,i,1)
MVC XDEC,=CL12' ' ~
MVC XDEC(L'CI),CI ci
XDECI R10,XDEC int(ci)
SLA R10,1 ii=int(ci)*2
IF CH,R10,GE,=H'10' THEN if ii>=10 then
SH R10,=H'9' ii=ii-9
ENDIF , endif
AR R9,R10 i2=i2+ii
LA R6,2(R6) i++
ENDDO , enddo i
LR R2,R8 i1
AR R2,R9 +i2
XDECO R2,XDEC s=str(i1+i2)
IF CLI,XDEC+11,EQ,C'0' THEN if substr(s,length(s),1)='0' then
MVC MSG,=CL6'OK' msg='ok'
ELSE , else
MVC MSG,=CL6'?err1' msg='?1'
ENDIF , endif
ELSE , else
MVC MSG,=CL6'?err2' msg='?2'
ENDIF , endif
ELSE , else
MVC MSG,=CL6'?err3' msg='?3'
ENDIF , endif
XDECO R7,XDEC edit j
MVC PG(2),XDEC+10 j
MVC PG+3(16),CC cc
MVC PG+20(6),MSG msg
XPRNT PG,L'PG print buffer
LA R7,1(R7) j++
ENDDO , enddo j
L R13,4(0,R13) restore previous savearea pointer
RETURN (14,12),RC=0 restore registers from calling sav
MVCX MVC 0(0,R4),0(R5) pattern svc INDEX SR R0,R0 index(r2,ci) r3=len
LA R1,1 k=1
SINDEXA CR R1,R3 do k=1 to length(ca)
BH SINDEXC ~
CLC 0(1,R2),CI if ca[k]=ci
BNE SINDEXB then iterate loop
LR R0,R1 ii=k
B SINDEXC exit loop
SINDEXB LA R2,1(R2) @ca++
LA R1,1(R1) k++
B SINDEXA enddo
SINDEXC BR R14 end index NN EQU (BASE36-TT)/16 number of items TT DC CL16'US0378331005',CL16'US0373831005'
DC CL16'U50378331005',CL16'US03378331005'
DC CL16'AU0000XVGZA3',CL16'AU0000VXGZA3'
DC CL16'FR0000988040'
BASE36 DC CL36'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ' ALPHA DC CL26'ABCDEFGHIJKLMNOPQRSTUVWXYZ' ERR DS X error LCC DS F length of cc LC DS F length of c CI DS CL1 CC DS CL16 current element of tt C DS CL28 R DS CL28 WW DS CL28 MSG DS CL6 message PG DC CL80' ' buffer XDEC DS CL12 temp for xdeco and xdeci
REGEQU
END VALISIN</lang>
- Output:
1 US0378331005 OK 2 US0373831005 ?err1 3 U50378331005 ?err2 4 US03378331005 ?err3 5 AU0000XVGZA3 OK 6 AU0000VXGZA3 OK 7 FR0000988040 OK
Ada
Calling the existing Luhn algorithm implementation from the Luhn test of credit card numbers task.
<lang Ada>procedure ISIN is
-- Luhn_Test copied from other Task
function Luhn_Test (Number: String) return Boolean is
Sum : Natural := 0;
Odd : Boolean := True;
Digit: Natural range 0 .. 9;
begin
for p in reverse Number'Range loop
Digit := Integer'Value (Number (p..p));
if Odd then
Sum := Sum + Digit;
else
Sum := Sum + (Digit*2 mod 10) + (Digit / 5);
end if;
Odd := not Odd;
end loop;
return (Sum mod 10) = 0;
end Luhn_Test;
subtype Decimal is Character range '0' .. '9';
subtype Letter is Character range 'A' .. 'Z';
subtype ISIN_Type is String(1..12);
-- converts a string of decimals and letters into a string of decimals
function To_Digits(S: String) return String is
-- Character'Pos('A')-Offset=10, Character'Pos('B')-Offset=11, ...
Offset: constant Integer := Character'Pos('A')-10;
Invalid_Character: exception;
begin
if S = "" then
return "";
elsif S(S'First) = ' ' then -- skip blanks
return To_Digits(S(S'First+1 .. S'Last));
elsif S(S'First) in Decimal then
return S(S'First) & To_Digits(S(S'First+1 .. S'Last));
elsif S(S'First) in Letter then
return To_Digits(Integer'Image(Character'Pos(S(S'First))-Offset))
& To_Digits(S(S'First+1 .. S'Last));
else
raise Invalid_Character;
end if;
end To_Digits;
function Is_Valid_ISIN(S: ISIN_Type) return Boolean is
Number : String := To_Digits(S);
begin
return S(S'First) in Letter and
S(S'First+1) in Letter and
S(S'Last) in Decimal and
Luhn_Test(Number);
end Is_Valid_ISIN;
Test_Cases : constant Array(1..6) of ISIN_Type :=
("US0378331005",
"US0373831005",
"U50378331005",
-- excluded by type with fixed length
-- "US03378331005",
"AU0000XVGZA3",
"AU0000VXGZA3",
"FR0000988040");
begin
for I in Test_Cases'Range loop
Ada.Text_IO.Put_Line(Test_Cases(I) & ":" &
Boolean'Image(Is_Valid_ISIN(Test_Cases(I))));
end loop;
-- using wrong length will result in an exception:
Ada.Text_IO.Put("US03378331005:");
Ada.Text_IO.Put_Line(Boolean'Image(Is_Valid_Isin("US03378331005")));
exception
when others =>
Ada.Text_IO.Put_Line("Exception occured");
end ISIN;</lang>
Output:
US0378331005:TRUE US0373831005:FALSE U50378331005:FALSE AU0000XVGZA3:TRUE AU0000VXGZA3:TRUE FR0000988040:TRUE US03378331005:Exception occured
ALGOL W
Uses the LuhnTest procedure from the Luhn test of credit card numbers task. <lang algolw>begin
% external procedure that returns true if ccNumber passes the Luhn test, false otherwise %
logical procedure LuhnTest ( string(32) value ccNumber
; integer value ccLength
) ; algol "LUHN" ;
% returns true if isin is a valid ISIN, false otherwise %
logical procedure isIsin ( string(32) value isin ) ;
if isin( 12 // 20 ) not = "" then false % code is too long %
else begin
% the first two characters must be upper-case letters %
% returns the digit corresponding to a character of an ISIN %
integer procedure isinDigit ( string(1) value iChar ) ;
if iChar >= "0" and iChar <= "9" then ( decode( iChar ) - decode( "0" ) )
else if iChar >= "A" and iChar <= "Z" then ( decode( iChar ) - decode( "A" ) ) + 10
else begin % invalid digit %
isValid := false;
-1
end isinDigit ;
integer d1, d2;
logical isValid;
isValid := true;
d1 := isinDigit( isin( 0 // 1 ) );
d2 := isinDigit( isin( 1 // 1 ) );
if d1 < 10 or d1 > 35 or d2 < 10 or d2 > 35 then false % invalid first two characters %
else begin
% ok so far - conveet from base 36 to base 10 %
string(24) base10Isin;
integer b10Pos;
base10Isin := "";
b10Pos := 0;
for cPos := 0 until 10 do begin
integer digit;
digit := isinDigit( isin( cPos // 1 ) );
if isValid then begin
% valid digit %
if digit > 9 then begin
base10Isin( b10Pos // 1 ) := code( ( digit div 10 ) + decode( "0" ) );
b10Pos := b10Pos + 1;
end if_digit_gt_9 ;
base10Isin( b10Pos // 1 ) := code( ( digit rem 10 ) + decode( "0" ) );
b10Pos := b10Pos + 1
end if_isValid
end for_cPos ;
% add the check digit as is %
base10Isin( b10Pos // 1 ) := isin( 11 // 1 );
isValid and LuhnTest( base10Isin, b10Pos + 1 )
end
end isIsin ;
% task test cases %
procedure testIsIsin ( string(32) value isin
; logical value expected
) ;
begin
logical isValid;
isValid := isIsin( isin );
write( s_w := 0
, isin
, if isValid then " is valid" else " is invalid"
, if isValid = expected then "" else " NOT as expected ??"
)
end testIsin ;
testIsIsin( "US0378331005", true ); testIsIsin( "US0373831005", false ); testIsIsin( "U50378331005", false ); testIsIsin( "US03378331005", false ); testIsIsin( "AU0000XVGZA3", true ); testIsIsin( "AU0000VXGZA3", true ); testIsIsin( "FR0000988040", true );
end.</lang>
- Output:
US0378331005 is valid US0373831005 is invalid U50378331005 is invalid US03378331005 is invalid AU0000XVGZA3 is valid AU0000VXGZA3 is valid FR0000988040 is valid
C
<lang c>#include <stdio.h>
int check_isin(char *a) {
int i, j, k, v, s[24];
j = 0;
for(i = 0; i < 12; i++) {
k = a[i];
if(k >= '0' && k <= '9') {
if(i < 2) return 0;
s[j++] = k - '0';
} else if(k >= 'A' && k <= 'Z') {
if(i == 11) return 0;
k -= 'A' - 10;
s[j++] = k / 10;
s[j++] = k % 10;
} else {
return 0;
}
}
if(a[i]) return 0;
v = 0;
for(i = j - 2; i >= 0; i -= 2) {
k = 2 * s[i];
v += k > 9 ? k - 9 : k;
}
for(i = j - 1; i >= 0; i -= 2) {
v += s[i];
}
return v % 10 == 0;
}
int main() {
char *test[7] = {"US0378331005", "US0373831005", "U50378331005",
"US03378331005", "AU0000XVGZA3", "AU0000VXGZA3",
"FR0000988040"};
int i;
for(i = 0; i < 7; i++) printf("%c%c", check_isin(test[i]) ? 'T' : 'F', i == 6 ? '\n' : ' ');
return 0;
}
/* will print: T F F F T T T */</lang>
C++
<lang cpp>
- include <string>
- include <regex>
- include <algorithm>
- include <numeric>
- include <sstream>
bool CheckFormat(const std::string& isin) { std::regex isinRegEpx(R"([A-Z]{2}[A-Z0-9]{9}[0-9])"); std::smatch match; return std::regex_match(isin, match, isinRegEpx); }
std::string CodeISIN(const std::string& isin) { std::string coded; int offset = 'A' - 10; for (auto ch : isin) { if (ch >= 'A' && ch <= 'Z') { std::stringstream ss; ss << static_cast<int>(ch) - offset; coded += ss.str(); } else { coded.push_back(ch); } }
return std::move(coded); }
bool CkeckISIN(const std::string& isin) { if (!CheckFormat(isin)) return false;
std::string coded = CodeISIN(isin); // from http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers#C.2B.2B11 return luhn(coded); }
- include <iomanip>
- include <iostream>
int main() { std::string isins[] = { "US0378331005", "US0373831005", "U50378331005", "US03378331005", "AU0000XVGZA3", "AU0000VXGZA3", "FR0000988040" }; for (const auto& isin : isins) { std::cout << isin << std::boolalpha << " - " << CkeckISIN(isin) <<std::endl; } return 0; } </lang>
C#
{ <lang csharp>using System; using System.Linq; using System.Text.RegularExpressions;
namespace Validate_ISIN {
public static class IsinValidator
{
public static bool IsValidIsin(string isin) =>
IsinRegex.IsMatch(isin) && LuhnTest(Digitize(isin));
private static readonly Regex IsinRegex =
new Regex("^[A-Z]{2}[A-Z0-9]{9}\\d$", RegexOptions.Compiled);
private static string Digitize(string isin) =>
string.Join("", isin.Select(c => $"{DigitValue(c)}"));
private static bool LuhnTest(string number) =>
number.Reverse().Select(DigitValue).Select(Summand).Sum() % 10 == 0;
private static int Summand(int digit, int i) =>
i % 2 == 0
? digit
: digit >= 5
? 2 * digit - 9
: 2 * digit;
private static int DigitValue(char c) =>
c >= '0' && c <= '9'
? c - '0'
: c - 'A' + 10;
}
public class Program
{
public static void Main(string[] args)
{
string[] isins = {
"US0378331005",
"US0373831005",
"U50378331005",
"US03378331005",
"AU0000XVGZA3",
"AU0000VXGZA3",
"FR0000988040"
};
foreach (string isin in isins) {
Console.WriteLine($"{isin} is {IsinValidator.IsValidIsin(isin) ? "valid" : "not valid"}");
}
}
}
}</lang>
- Output:
US0378331005 is valid US0373831005 is not valid U50378331005 is not valid US03378331005 is not valid AU0000XVGZA3 is valid AU0000VXGZA3 is valid FR0000988040 is valid
Caché ObjectScript
<lang cos>Class Utils.Check [ Abstract ] {
ClassMethod ISIN(x As %String) As %Boolean { // https://en.wikipedia.org/wiki/International_Securities_Identification_Number IF x'?2U9UN1N QUIT 0 SET cd=$EXTRACT(x,*), x=$EXTRACT(x,1,*-1) FOR i=1:1 { SET n=$EXTRACT(x,i) IF n="" QUIT IF n'=+n SET $EXTRACT(x,i)=$CASE(n,"*":36,"@":37,"#":38,:$ASCII(n)-55) } // call into luhn check, appending check digit QUIT ..Luhn(x_cd) }
ClassMethod Luhn(x As %String) As %Boolean { // https://www.simple-talk.com/sql/t-sql-programming/calculating-and-verifying-check-digits-in-t-sql/ SET x=$TRANSLATE(x," "), cd=$EXTRACT(x,*) SET x=$REVERSE($EXTRACT(x,1,*-1)), t=0 FOR i=1:1:$LENGTH(x) { SET n=$EXTRACT(x,i) IF i#2 SET n=n*2 IF $LENGTH(n)>1 SET n=$EXTRACT(n,1)+$EXTRACT(n,2) SET t=t+n } QUIT cd=((t*9)#10) }
}</lang>
- Examples:
USER>For { Read isin Quit:isin="" Write ": "_##class(Utils.Check).ISIN(isin), ! }
US0378331005: 1
US0373831005: 0
U50378331005: 0
US03378331005: 0
AU0000XVGZA3: 1
AU0000VXGZA3: 1
FR0000988040: 1
USER>
Clojure
<lang clojure>(defn luhn? [cc]
(let [sum (->> cc
(map #(Character/digit ^char % 10))
reverse
(map * (cycle [1 2]))
(map #(+ (quot % 10) (mod % 10)))
(reduce +))]
(zero? (mod sum 10))))
(defn is-valid-isin? [isin]
(and (re-matches #"^[A-Z]{2}[A-Z0-9]{9}[0-9]$" isin)
(->> isin
(map #(Character/digit ^char % 36))
(apply str)
luhn?)))
(use 'clojure.pprint) (doseq [isin ["US0378331005" "US0373831005" "U50378331005" "US03378331005"
"AU0000XVGZA3" "AU0000VXGZA3" "FR0000988040"]] (cl-format *out* "~A: ~:[invalid~;valid~]~%" isin (is-valid-isin? isin)))
</lang> luhn? is based on Luhn test of credit card numbers#Clojure.
- Output:
US0378331005: valid US0373831005: invalid U50378331005: invalid US03378331005: invalid AU0000XVGZA3: valid AU0000VXGZA3: valid FR0000988040: valid
COBOL
<lang cobol> >>SOURCE FORMAT FREE
- > this is gnucobol 2.0
identification division. program-id. callISINtest. data division. working-storage section. 01 ISINtest-result binary-int. procedure division. start-callISINtest.
display 'should be valid ' with no advancing call 'ISINtest' using 'US0378331005' ISINtest-result perform display-ISINtest-result display 'should not be valid ' with no advancing call 'ISINtest' using 'US0373831005' ISINtest-result perform display-ISINtest-result display 'should not be valid ' with no advancing call 'ISINtest' using 'U50378331005' ISINtest-result perform display-ISINtest-result display 'should not be valid ' with no advancing call 'ISINtest' using 'US03378331005' ISINtest-result perform display-ISINtest-result display 'should be valid ' with no advancing call 'ISINtest' using 'AU0000XVGZA3' ISINtest-result perform display-ISINtest-result display 'should be valid ' with no advancing call 'ISINtest' using 'AU0000VXGZA3' ISINtest-result perform display-ISINtest-result display 'should be valid ' with no advancing call 'ISINtest' using 'FR0000988040' ISINtest-result perform display-ISINtest-result stop run .
display-ISINtest-result.
evaluate ISINtest-result
when 0
display ' is valid'
when -1
display ' invalid length '
when -2
display ' invalid countrycode '
when -3
display ' invalid base36 digit '
when -4
display ' luhn test failed'
when other
display ' invalid return code ' ISINtest-result
end-evaluate
.
end program callISINtest.
identification division. program-id. ISINtest. data division. working-storage section. 01 country-code-values value
'ADAEAFAGAIALAMAOAQARASATAUAWAXAZBABBBDBEBFBGBHBIBJBLBMBNBOBQBRBS'
& 'BTBVBWBYBZCACCCDCFCGCHCICKCLCMCNCOCRCUCVCWCXCYCZDEDJDKDMDODZECEE' & 'EGEHERESETFIFJFKFMFOFRGAGBGDGEGFGGGHGIGLGMGNGPGQGRGSGTGUGWGYHKHM' & 'HNHRHTHUIDIEILIMINIOIQIRISITJEJMJOJPKEKGKHKIKMKNKPKRKWKYKZLALBLC' & 'LILKLRLSLTLULVLYMAMCMDMEMFMGMHMKMLMMMNMOMPMQMRMSMTMUMVMWMXMYMZNA' & 'NCNENFNGNINLNONPNRNUNZOMPAPEPFPGPHPKPLPMPNPRPSPTPWPYQARERORSRURW' & 'SASBSCSDSESGSHSISJSKSLSMSNSOSRSSSTSVSXSYSZTCTDTFTGTHTJTKTLTMTNTO' & 'TRTTTVTWTZUAUGUMUSUYUZVAVCVEVGVIVNVUWFWSYEYTZAZMZW'.
03 country-codes occurs 249
ascending key country-code
indexed by cc-idx.
05 country-code pic xx.
01 b pic 99. 01 base36-digits pic x(36) value
'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'.
01 i pic 99. 01 p pic 99. 01 luhn-number pic x(20). 01 luhntest-result binary-int.
linkage section. 01 test-number any length. 01 ISINtest-result binary-int.
procedure division using test-number ISINtest-result. start-ISINtest.
display space test-number with no advancing
*> format test
if function length(test-number) <> 12
move -1 to ISINtest-result
goback
end-if
*> countrycode test
search all country-codes
at end
move -2 to ISINtest-result
goback
when test-number(1:2) = country-code(cc-idx)
continue
end-search
*> convert each character from base 36 to base 10
*> and add to the luhn-number
move 0 to p
perform varying i from 1 by 1 until i > 12
if test-number(i:1) >= '0' and <= '9'
move test-number(i:1) to luhn-number(p + 1:1)
add 1 to p
else
perform varying b from 9 by 1 until b > 35
or base36-digits(b + 1:1) = test-number(i:1)
continue
end-perform
if b > 35
move -3 to ISINtest-result
goback
end-if
move b to luhn-number(p + 1:2)
add 2 to p
end-if
end-perform
call 'luhntest' using luhn-number(1:p) luhntest-result
if luhntest-result <> 0
move -4 to ISINtest-result
goback
end-if
move 0 to ISINtest-result goback .
end program ISINtest.
identification division. program-id. luhntest. data division. working-storage section. 01 i pic S99. 01 check-sum pic 999. linkage section. 01 test-number any length. 01 luhntest-result binary-int. procedure division using test-number luhntest-result. start-luhntest.
display space test-number with no advancing move 0 to check-sum
*> right to left sum the odd numbered digits
compute i = function length(test-number)
perform varying i from i by -2 until i < 1
add function numval(test-number(i:1)) to check-sum
end-perform
display space check-sum with no advancing
*> right to left double sum the even numbered digits
compute i = function length(test-number) - 1
perform varying i from i by -2 until i < 1
add function numval(test-number(i:1)) to check-sum
add function numval(test-number(i:1)) to check-sum
*> convert a two-digit double sum number to a single digit
if test-number(i:1) >= '5'
subtract 9 from check-sum
end-if
end-perform
display space check-sum with no advancing
if function mod(check-sum,10) = 0
move 0 to luhntest-result *> success
else
move -1 to luhntest-result *> failure
end-if
goback
.
end program luhntest.</lang>
- Output:
prompt$ cobc -xj ISINTest.cbl should be valid US0378331005 30280378331005 027 050 is valid should not be valid US0373831005 30280373831005 022 046 luhn test failed should not be valid U50378331005 invalid countrycode should not be valid US03378331005 invalid length should be valid AU0000XVGZA3 1030000033311635103 018 030 is valid should be valid AU0000VXGZA3 1030000031331635103 018 030 is valid should be valid FR0000988040 15270000988040 020 050 is valid
Common Lisp
<lang lisp>(defun alphap (char)
(char<= #\A char #\Z))
(defun alpha-digit-char-p (char)
(or (alphap char) (digit-char-p char)))
(defun valid-isin-format-p (isin)
(and (= (length isin) 12)
(alphap (char isin 0))
(alphap (char isin 1))
(loop for i from 2 to 10
always (alpha-digit-char-p (char isin i)))
(digit-char-p (char isin 11))))
(defun isin->digits (isin)
(apply #'concatenate 'string
(loop for c across isin
collect (princ-to-string (digit-char-p c 36)))))
(defun luhn-test (string)
(loop for c across (reverse string)
for oddp = t then (not oddp)
if oddp
sum (digit-char-p c) into result
else
sum (let ((n (* 2 (digit-char-p c))))
(if (> n 9) (- n 9) n))
into result
finally (return (zerop (mod result 10)))))
(defun valid-isin-p (isin)
(and (valid-isin-format-p isin)
(luhn-test (isin->digits isin))))
(defun test ()
(dolist (isin '("US0378331005" "US0373831005" "U50378331005" "US03378331005"
"AU0000XVGZA3" "AU0000VXGZA3" "FR0000988040"))
(format t "~A: ~:[invalid~;valid~]~%" isin (valid-isin-p isin))))</lang>
- Output:
US0378331005: valid US0373831005: invalid U50378331005: invalid US03378331005: invalid AU0000XVGZA3: valid AU0000VXGZA3: valid FR0000988040: valid
D
Code for the luhn test was taken from [[1]] <lang D>import std.stdio;
void main() {
auto isins = [
"US0378331005",
"US0373831005",
"U50378331005",
"US03378331005",
"AU0000XVGZA3",
"AU0000VXGZA3",
"FR0000988040",
];
foreach (isin; isins) {
writeln(isin, " is ", ISINvalidate(isin) ? "valid" : "not valid");
}
}
bool ISINvalidate(string isin) {
import std.array : appender; import std.conv : to; import std.regex : matchFirst; import std.string : strip, toUpper;
isin = isin.strip.toUpper;
if (isin.matchFirst(`^[A-Z]{2}[A-Z0-9]{9}\d$`).empty) {
return false;
}
auto sb = appender!string;
foreach (c; isin[0..12]) {
sb.put(
[c].to!int(36)
.to!string
);
}
import luhn; return luhnTest(sb.data);
}</lang>
- Output:
US0378331005 is valid US0373831005 is not valid U50378331005 is not valid US03378331005 is not valid AU0000XVGZA3 is valid AU0000VXGZA3 is valid FR0000988040 is valid
Elixir
used Luhn module from here <lang elixir>isin? = fn str ->
if str =~ ~r/\A[A-Z]{2}[A-Z0-9]{9}\d\z/ do
String.codepoints(str)
|> Enum.map_join(&String.to_integer(&1, 36))
|> Luhn.valid?
else
false
end
end
IO.puts " ISIN Valid?" ~w(US0378331005
US0373831005 U50378331005 US03378331005 AU0000XVGZA3 AU0000VXGZA3 FR0000988040)
|> Enum.each(&IO.puts "#{&1}\t#{isin?.(&1)}")</lang>
- Output:
ISIN Valid? US0378331005 true US0373831005 false U50378331005 false US03378331005 false AU0000XVGZA3 true AU0000VXGZA3 true FR0000988040 true
Factor
We re-use the luhn? word from Luhn test of credit card numbers#Factor.
<lang factor>USING: combinators.short-circuit.smart formatting kernel luhn
math math.parser qw sequences strings unicode ;
IN: rosetta-code.isin
CONSTANT: test-cases qw{
US0378331005 US0373831005 U50378331005 US03378331005 AU0000XVGZA3 AU0000VXGZA3 FR0000988040
}
- valid-length? ( str -- ? ) length 12 = ;
- valid-country-code? ( str -- ? ) first2 [ Letter? ] both? ;
- valid-security-code? ( str -- ? )
[ 2 11 ] dip subseq [ alpha? ] all? ;
- valid-checksum-digit? ( str -- ? ) last digit? ;
- valid-format? ( str -- ? ) {
[ valid-length? ]
[ valid-country-code? ]
[ valid-security-code? ]
[ valid-checksum-digit? ]
} && ;
- base36>base10 ( str -- n )
>upper [ dup LETTER? [ 55 - number>string ] [ 1string ] if ]
{ } map-as concat string>number ;
- isin? ( str -- ? )
{ [ valid-format? ] [ base36>base10 luhn? ] } && ;
- main ( -- )
test-cases [
dup isin? "" " not" ? "%s is%s valid\n" printf
] each ;
MAIN: main</lang>
- Output:
US0378331005 is valid US0373831005 is not valid U50378331005 is not valid US03378331005 is not valid AU0000XVGZA3 is valid AU0000VXGZA3 is valid FR0000988040 is valid
Fortran
<lang fortran>program isin
use ctype
implicit none
character(20) :: test(7) = ["US0378331005 ", &
"US0373831005 ", &
"U50378331005 ", &
"US03378331005 ", &
"AU0000XVGZA3 ", &
"AU0000VXGZA3 ", &
"FR0000988040 "]
print *, check_isin(test)
contains
elemental logical function check_isin(a)
character(*), intent(in) :: a
integer :: s(24)
integer :: i, j, k, n, v
check_isin = .false.
n = len_trim(a)
if (n /= 12) return
! Convert to an array of digits
j = 0
do i = 1, n
k = iachar(a(i:i))
if (k >= 48 .and. k <= 57) then
if (i < 3) return
k = k - 48
j = j + 1
s(j) = k
else if (k >= 65 .and. k <= 90) then
if (i == 12) return
k = k - 65 + 10
j = j + 1
s(j) = k / 10
j = j + 1
s(j) = mod(k, 10)
else
return
end if
end do
! Compute checksum
v = 0
do i = j - 1, 1, -2
k = 2 * s(i)
if (k > 9) k = k - 9
v = v + k
end do
do i = j, 1, -2
v = v + s(i)
end do
check_isin = 0 == mod(v, 10)
end function
end program</lang>
FreeBASIC
<lang freebasic>' version 27-10-2016 ' compile with: fbc -s console
- Ifndef TRUE ' define true and false for older freebasic versions
#Define FALSE 0 #Define TRUE Not FALSE
- EndIf
Function luhntest(cardnr As String) As Long
cardnr = Trim(cardnr) ' remove spaces
Dim As String reverse_nr = cardnr Dim As Long i, j, s1, s2, l = Len(cardnr) -1
' reverse string
For i = 0 To l
reverse_nr[i] = cardnr[l - i]
Next
' sum odd numbers
For i = 0 To l Step 2
s1 = s1 + (reverse_nr[i] - Asc("0"))
Next
' sum even numbers
For i = 1 To l Step 2
j = reverse_nr[i] - Asc("0")
j = j * 2
If j > 9 Then j = j Mod 10 +1
s2 = s2 + j
Next
If (s1 + s2) Mod 10 = 0 Then
Return TRUE
Else
Return FALSE
End If
End Function
' ------=< MAIN >=-----
Dim As String test_str Dim As String test_set(1 To ...) = { "US0378331005", "US0373831005", _
"U50378331005", "US03378331005", "AU0000XVGZA3", _
"AU0000VXGZA3", "FR0000988040" }
Dim As Long i, l, n, x
For i = 1 To UBound(test_set)
test_str = ""
l = Len(test_set(i))
If l <> 12 Then
Print test_set(i), "Invalid, length <> 12 char."
Continue For
End If
If test_set(i)[0] < Asc("A") Or test_set(i)[1] < Asc("A") Then
Print test_set(i), "Invalid, number needs to start with 2 characters"
Continue For
End If
For n = 0 To l -1
x = test_set(i)[n] - Asc("0")
' if test_set(i)[i] is a letter we to correct for that
If x > 9 Then x = x -7
If x < 10 Then
test_str = test_str + Str(x)
Else ' two digest number
test_str = test_str + Str(x \ 10) + Str(x Mod 10)
End If
Next
Print test_set(i), IIf(luhntest(test_str) = TRUE, "Valid","Invalid, checksum error")
Next
' empty keyboard buffer
While InKey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End</lang>
- Output:
US0378331005 Valid US0373831005 Invalid, checksum error U50378331005 Invalid, number needs to start with 2 characters US03378331005 Invalid, length <> 12 char. AU0000XVGZA3 Valid AU0000VXGZA3 Valid FR0000988040 Valid
Go
<lang go>package main
import "regexp"
var r = regexp.MustCompile(`^[A-Z]{2}[A-Z0-9]{9}\d$`)
var inc = [2][10]int{ {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}, {0, 2, 4, 6, 8, 1, 3, 5, 7, 9}, }
func ValidISIN(n string) bool { if !r.MatchString(n) { return false } var sum, p int for i := 10; i >= 0; i-- { p = 1 - p if d := n[i]; d < 'A' { sum += inc[p][d-'0'] } else { d -= 'A' sum += inc[p][d%10] p = 1 - p sum += inc[p][d/10+1] } } sum += int(n[11] - '0') return sum%10 == 0 }</lang>
<lang go>package main
import "testing"
func TestValidISIN(t *testing.T) { testcases := []struct { isin string valid bool }{ {"US0378331005", true}, {"US0373831005", false}, {"U50378331005", false}, {"US03378331005", false}, {"AU0000XVGZA3", true}, {"AU0000VXGZA3", true}, {"FR0000988040", true}, }
for _, testcase := range testcases { actual := ValidISIN(testcase.isin) if actual != testcase.valid { t.Errorf("expected %v for %q, got %v", testcase.valid, testcase.isin, actual) } } }</lang>
Groovy
<lang groovy>CHARS = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'
int checksum(String prefix) {
def digits = prefix.toUpperCase().collect { CHARS.indexOf(it).toString() }.sum()
def groups = digits.collect { CHARS.indexOf(it) }.inject([[], []]) { acc, i -> [acc[1], acc[0] + i] }
def ds = groups[1].collect { (2 * it).toString() }.sum().collect { CHARS.indexOf(it) } + groups[0]
(10 - ds.sum() % 10) % 10
}
assert checksum('AU0000VXGZA') == 3 assert checksum('GB000263494') == 6 assert checksum('US037833100') == 5 assert checksum('US037833107') == 0</lang>
Haskell
<lang Haskell>module ISINVerification2 where
import Data.Char (isUpper, isDigit, digitToInt)
verifyISIN :: String -> Bool verifyISIN isin =
correctFormat isin && mod (oddsum + multiplied_even_sum) 10 == 0 where reverted = reverse $ convertToNumber isin theOdds = fst $ collectOddandEven reverted theEvens = snd $ collectOddandEven reverted oddsum = sum $ map digitToInt theOdds multiplied_even_sum = addUpDigits $ map ((* 2) . digitToInt) theEvens
capitalLetters :: String capitalLetters = ['A','B' .. 'Z']
numbers :: String numbers = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
correctFormat :: String -> Bool correctFormat isin =
(length isin == 12) && all (`elem` capitalLetters) (take 2 isin) && all (\c -> elem c capitalLetters || elem c numbers) (drop 2 $ take 11 isin) && elem (last isin) numbers
convertToNumber :: String -> String convertToNumber = concatMap convert
where
convert :: Char -> String
convert c =
if isDigit c
then show $ digitToInt c
else show (fromEnum c - 55)
collectOddandEven :: String -> (String, String) collectOddandEven term
| odd $ length term =
( concat
[ take 1 $ drop n term
| n <- [0,2 .. length term - 1] ]
, concat
[ take 1 $ drop d term
| d <- [1,3 .. length term - 2] ])
| otherwise =
( concat
[ take 1 $ drop n term
| n <- [0,2 .. length term - 2] ]
, concat
[ take 1 $ drop d term
| d <- [1,3 .. length term - 1] ])
addUpDigits :: [Int] -> Int addUpDigits list =
sum $
map
(\d ->
if d > 9
then sum $ map digitToInt $ show d
else d)
list
printSolution :: String -> IO () printSolution str = do
putStr $ str ++ " is" if verifyISIN str then putStrLn " valid" else putStrLn " not valid"
main :: IO () main = do
let isinnumbers =
[ "US0378331005"
, "US0373831005"
, "U50378331005"
, "US03378331005"
, "AU0000XVGZA3"
, "AU0000VXGZA3"
, "FR0000988040"
]
mapM_ printSolution isinnumbers</lang>
- Output:
US0378331005 is valid US0373831005 is not valid U50378331005 is not valid US03378331005 is not valid AU0000XVGZA3 is valid AU0000VXGZA3 is valid FR0000988040 is valid
Or, making alternative choices from standard libraries: <lang haskell>import qualified Data.Map as M import Data.Maybe (fromMaybe)
validISIN, isinPattern, luhn :: String -> Bool validISIN = (&&) <$> isinPattern <*> (luhn . (show =<<) . stringInts)
isinPattern s =
12 == length s &&
let [l, m, r] = bites [2, 9, 1] s
in all (`elem` capitals) l &&
all (`elem` (capitals ++ digits)) m && head r `elem` digits
luhn x =
let odd = [(: []), const []]
even = reverse odd
stream f = concat $ zipWith ($) (cycle f) (stringInts $ reverse x)
s1 = sum (stream odd)
s2 = sum $ sum . stringInts . show . (2 *) <$> stream even
in rem (s1 + s2) 10 == 0
charMap :: M.Map Char Int charMap = M.fromList $ zip (digits ++ capitals) [0 ..]
stringInts :: String -> [Int] stringInts = fromMaybe [] . sequence . fmap (`M.lookup` charMap)
bites :: [Int] -> [a] -> a bites ns xs =
reverse . fst $
foldr
(\x (a, r) ->
let (b, r_) = splitAt x r
in (b : a, r_))
([], xs)
(reverse ns)
capitals, digits :: String capitals = ['A' .. 'Z']
digits = ['0' .. '9']
main :: IO () main =
mapM_ (print . ((,) <*> validISIN)) [ "US0378331005" , "US0373831005" , "U50378331005" , "US03378331005" , "AU0000XVGZA3" , "AU0000VXGZA3" , "FR0000988040" ]</lang>
- Output:
("US0378331005",True)
("US0373831005",False)
("U50378331005",False)
("US03378331005",False)
("AU0000XVGZA3",True)
("AU0000VXGZA3",True)
("FR0000988040",True)
J
Solution: <lang j>require'regex' validFmt=: 0 -: '^[A-Z]{2}[A-Z0-9]{9}[0-9]{1}$'&rxindex
df36=: ;@([: <@":"0 '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'&i.) NB. decimal from base 36 luhn=: 0 = 10 (| +/@,) 10 #.inv 1 2 *&|: _2 "."0\ |. NB. as per task Luhn_test_of_credit_card_numbers#J
validISIN=: validFmt *. luhn@df36</lang>
Required Examples: <lang j> Tests=: 'US0378331005';'US0373831005';'U50378331005';'US03378331005';'AU0000XVGZA3';'AU0000VXGZA3';'FR0000988040'
validISIN&> Tests
1 0 0 0 1 1 1</lang>
Java
As the Luhn test method from the Luhn test of credit card numbers task is only a few lines, it has been embedded in the ISIN class for convenience.
<lang java>public class ISIN {
public static void main(String[] args) {
String[] isins = {
"US0378331005",
"US0373831005",
"U50378331005",
"US03378331005",
"AU0000XVGZA3",
"AU0000VXGZA3",
"FR0000988040"
};
for (String isin : isins)
System.out.printf("%s is %s\n", isin, ISINtest(isin) ? "valid" : "not valid");
}
static boolean ISINtest(String isin) {
isin = isin.trim().toUpperCase();
if (!isin.matches("^[A-Z]{2}[A-Z0-9]{9}\\d$"))
return false;
StringBuilder sb = new StringBuilder();
for (char c : isin.substring(0, 12).toCharArray())
sb.append(Character.digit(c, 36));
return luhnTest(sb.toString());
}
static boolean luhnTest(String number) {
int s1 = 0, s2 = 0;
String reverse = new StringBuffer(number).reverse().toString();
for (int i = 0; i < reverse.length(); i++){
int digit = Character.digit(reverse.charAt(i), 10);
//This is for odd digits, they are 1-indexed in the algorithm.
if (i % 2 == 0){
s1 += digit;
} else { // Add 2 * digit for 0-4, add 2 * digit - 9 for 5-9.
s2 += 2 * digit;
if(digit >= 5){
s2 -= 9;
}
}
}
return (s1 + s2) % 10 == 0;
}
}</lang>
US0378331005 is valid US0373831005 is not valid U50378331005 is not valid US03378331005 is not valid AU0000XVGZA3 is valid AU0000VXGZA3 is valid FR0000988040 is valid
Julia
<lang julia>using Printf
luhntest(x) = luhntest(parse(Int, x))
function checkISIN(inum::AbstractString)
if length(inum) != 12 || !all(isalpha, inum[1:2]) return false end return parse.(Int, collect(inum), 36) |> join |> luhntest
end
for inum in ["US0378331005", "US0373831005", "U50378331005",
"US03378331005", "AU0000XVGZA3", "AU0000VXGZA3", "FR0000988040"]
@printf("%-15s %5s\n", inum, ifelse(checkISIN(inum), "pass", "fail"))
end</lang>
- Output:
US0378331005 pass US0373831005 fail U50378331005 fail US03378331005 fail AU0000XVGZA3 pass AU0000VXGZA3 pass FR0000988040 pass
Kotlin
As the Luhn test method is only a few lines, it's reproduced here for convenience: <lang scala>// version 1.1
object Isin {
val r = Regex("^[A-Z]{2}[A-Z0-9]{9}[0-9]$")
fun isValid(s: String): Boolean {
// check format
if (!s.matches(r)) return false
// validate checksum
val sb = StringBuilder()
for (c in s) {
when (c) {
in '0'..'9' -> sb.append(c)
in 'A'..'Z' -> sb.append((c.toInt() - 55).toString().padStart(2, '0'))
}
}
return luhn(sb.toString())
}
private fun luhn(s: String): Boolean {
fun sumDigits(n: Int) = n / 10 + n % 10
val t = s.reversed()
val s1 = t.filterIndexed { i, _ -> i % 2 == 0 }.sumBy { it - '0' }
val s2 = t.filterIndexed { i, _ -> i % 2 == 1 }.map { sumDigits((it - '0') * 2) }.sum()
return (s1 + s2) % 10 == 0
}
}
fun main(args: Array<String>) {
val isins = arrayOf(
"US0378331005", "US0373831005", "U50378331005", "US03378331005",
"AU0000XVGZA3", "AU0000VXGZA3", "FR0000988040"
)
for (isin in isins) {
println("$isin\t -> ${if (Isin.isValid(isin)) "valid" else "not valid"}")
}
}</lang>
- Output:
US0378331005 -> valid US0373831005 -> not valid U50378331005 -> not valid US03378331005 -> not valid AU0000XVGZA3 -> valid AU0000VXGZA3 -> valid FR0000988040 -> valid
langur
The luhn test is repeated here for simplicity (from Luhn_test_of_credit_card_numbers#langur).
<lang langur>val .luhntest = f(.s) {
val .t = [0, 2, 4, 6, 8, 1, 3, 5, 7, 9] val .numbers = map f .c-'0', s2cp .s val .oddeven = len(.numbers) rem 2
foldfrom(
f(.sum, .i, .c) if .i rem 2 == .oddeven { .sum + .c } else { .sum + .t[.c+1] },
0,
series len .numbers,
.numbers,
) rem 10 == 0
}
val .isintest = f(.s) {
if not matching(re/^[A-Z][A-Z][0-9A-Z]{9}[0-9]$/, .s) {
return false
}
.luhntest(join map f toNumber(.c, 36), split .s)
# used unbounded lists on join(), map(), and split()...
# ... and implied parameters and a single expression on the anonymous function
# same as .luhntest(join(map(f(.c) { toNumber(.c, 36) }, split(.s))))
}
val .tests = h{
"US0378331005": true, "US0373831005": false, "U50378331005": false, "AU0000XVGZA3": true, "AU0000VXGZA3": true, "FR0000988040": true, "US03378331005": false,
}
for .key in sort(keys .tests) {
val .pass = .isintest(.key) write .key, ": ", .pass writeln if(.pass == .tests[.key]: ""; " (ISIN TEST FAILED)")
}</lang>
- Output:
AU0000VXGZA3: true AU0000XVGZA3: true FR0000988040: true U50378331005: false US03378331005: false US0373831005: false US0378331005: true
Lua
<lang Lua>function luhn (n)
local revStr, s1, s2, digit, mod = n:reverse(), 0, 0
for pos = 1, #revStr do
digit = tonumber(revStr:sub(pos, pos))
if pos % 2 == 1 then
s1 = s1 + digit
else
digit = digit * 2
if digit > 9 then
mod = digit % 10
digit = mod + ((digit - mod) / 10)
end
s2 = s2 + digit
end
end
return (s1 + s2) % 10 == 0
end
function checkISIN (inStr)
if #inStr ~= 12 then return false end
local numStr = ""
for pos = 1, #inStr do
numStr = numStr .. tonumber(inStr:sub(pos, pos), 36)
end
return luhn(numStr)
end
local testCases = {
"US0378331005", "US0373831005", "US0373831005", "US03378331005", "AU0000XVGZA3", "AU0000VXGZA3", "FR0000988040"
} for _, ISIN in pairs(testCases) do print(ISIN, checkISIN(ISIN)) end</lang>
- Output:
US0378331005 true US0373831005 false US0373831005 false US03378331005 false AU0000XVGZA3 true AU0000VXGZA3 true FR0000988040 true
Perl
We reuse the luhn_test() function from Luhn test of credit card numbers#Perl. <lang perl>use strict; use English; use POSIX; use Test::Simple tests => 7;
ok( validate_isin('US0378331005'), 'Test 1'); ok( ! validate_isin('US0373831005'), 'Test 2'); ok( ! validate_isin('U50378331005'), 'Test 3'); ok( ! validate_isin('US03378331005'), 'Test 4'); ok( validate_isin('AU0000XVGZA3'), 'Test 5'); ok( validate_isin('AU0000VXGZA3'), 'Test 6'); ok( validate_isin('FR0000988040'), 'Test 7'); exit 0;
sub validate_isin {
my $isin = shift;
$isin =~ /\A[A-Z]{2}[A-Z\d]{9}\d\z/s or return 0;
my $base10 = join(q{}, map {scalar(POSIX::strtol($ARG, 36))}
split(//s, $isin));
return luhn_test($base10);
}</lang>
- Output:
1..7 ok 1 - Test 1 ok 2 - Test 2 ok 3 - Test 3 ok 4 - Test 4 ok 5 - Test 5 ok 6 - Test 6 ok 7 - Test 7
Perl 6
Using the luhn-test function from the Luhn test of credit card numbers task.
<lang perl6>my $ISIN = /
^ <[A..Z]>**2 <[A..Z0..9]>**9 <[0..9]> $
<?{ luhn-test $/.comb.map({ :36($_) }).join }>
/;
sub luhn-test ($number --> Bool) {
my @digits = $number.comb.reverse;
my $sum = @digits[0,2...*].sum
+ @digits[1,3...*].map({ |($_ * 2).comb }).sum;
return $sum %% 10;
}
- Testing:
say "$_ is { m/$ISIN/ ?? "valid" !! "not valid"}" for < US0378331005 US0373831005 U50378331005 US03378331005 AU0000XVGZA3 AU0000VXGZA3 FR0000988040 >;</lang>
- Output:
US0378331005 is valid US0373831005 is not valid U50378331005 is not valid US03378331005 is not valid AU0000XVGZA3 is valid AU0000VXGZA3 is valid FR0000988040 is valid
Phix
Note this (slightly better) version of Luhn() has the reverse() inside it, whereas the original did not. <lang Phix>function Luhn(string st) integer s=0, d
st = reverse(st)
for i=1 to length(st) do
d = st[i]-'0'
s += iff(mod(i,2)?d,d*2-(d>4)*9)
end for
return remainder(s,10)=0
end function
function valid_ISIN(string st) -- returns 1 if valid, else 0/2/3/4. -- (feel free to return 0 instead of 2/3/4)
if length(st)!=12 then return 2 end if
for i=length(st) to 1 by -1 do
integer ch = st[i]
if ch>='A' then
if ch>'Z' then return 3 end if
st[i..i] = sprintf("%d",ch-55)
elsif i<=2 then
return 4
elsif ch<'0' or ch>'9' then
return 3
end if
end for
return Luhn(st)
end function
sequence tests = {"US0378331005", -- valid
"US0373831005", -- not valid The transposition typo is caught by the checksum constraint.
"U50378331005", -- not valid The substitution typo is caught by the format constraint.
"US03378331005", -- not valid The duplication typo is caught by the format constraint.
"AU0000XVGZA3", -- valid
"AU0000VXGZA3", -- valid Unfortunately, not all transposition typos are caught by the checksum constraint.
"FR0000988040"} -- valid
constant reasons = {"wrong checksum","valid","wrong length","bad char","wrong country"}
for i=1 to length(tests) do
string ti = tests[i]
printf(1,"%s : %s\n",{ti,reasons[valid_ISIN(ti)+1]})
end for</lang>
- Output:
US0378331005 : valid US0373831005 : wrong checksum U50378331005 : wrong country US03378331005 : wrong length AU0000XVGZA3 : valid AU0000VXGZA3 : valid FR0000988040 : valid
PicoLisp
Using the luhn function defined at Luhn test of credit card numbers#PicoLisp: <lang PicoLisp>(de isin (Str)
(let Str (mapcar char (chop Str))
(and
(= 12 (length Str))
(<= 65 (car Str) 90)
(<= 65 (cadr Str) 90)
(luhn
(pack
(mapcar
'((N)
(- N (if (<= 48 N 57) 48 55)) )
Str ) ) ) ) ) )
(println
(mapcar
isin
(quote
"US0378331005"
"US0373831005"
"U50378331005"
"US03783310005"
"AU0000XVGZA3"
"AU0000VXGZA3"
"FR0000988040" ) ) )</lang>
- Output:
(0 NIL NIL NIL 0 0 0)
PowerShell
<lang PowerShell> function Test-ISIN {
[CmdletBinding()]
[OutputType([bool])]
Param
(
[Parameter(Mandatory=$true, Position=0)]
[ValidatePattern("[A-Z]{2}\w{9}\d")]
[ValidateScript({$_.Length -eq 12})]
[string]
$Number
)
function Split-Array
{
$array = @(), @()
$input | ForEach-Object {$array[($index = -not $index)] += $_}
$array[1], $array[0]
}
filter ConvertTo-Digit
{
if ($_ -gt 9)
{
$_.ToString().ToCharArray() | ForEach-Object -Begin {$n = 0} -Process {$n += [Char]::GetNumericValue($_)} -End {$n}
}
else
{
$_
}
}
$checkDigit = $Number[-1]
$digits = ($Number -replace ".$").ToCharArray() | ForEach-Object {
if ([Char]::IsDigit($_))
{
[Char]::GetNumericValue($_)
}
else
{
[int][char]$_ - 55
}
}
$odds, $evens = ($digits -join "").ToCharArray() | Split-Array
if ($odds.Count -gt $evens.Count)
{
$odds = $odds | ForEach-Object {[Char]::GetNumericValue($_) * 2} | ConvertTo-Digit
$evens = $evens | ForEach-Object {[Char]::GetNumericValue($_)}
}
else
{
$odds = $odds | ForEach-Object {[Char]::GetNumericValue($_)}
$evens = $evens | ForEach-Object {[Char]::GetNumericValue($_) * 2} | ConvertTo-Digit
}
$sum = ($odds | Measure-Object -Sum).Sum + ($evens | Measure-Object -Sum).Sum
(10 - ($sum % 10)) % 10 -match $checkDigit
} </lang> <lang PowerShell> "US0378331005","US0373831005","US0337833103","AU0000XVGZA3","AU0000VXGZA3","FR0000988040" | ForEach-Object {
[PSCustomObject]@{
ISIN = $_
IsValid = Test-ISIN -Number $_
}
} </lang>
- Output:
ISIN IsValid ---- ------- US0378331005 True US0373831005 False US0337833103 False AU0000XVGZA3 True AU0000VXGZA3 True FR0000988040 True
PureBasic
<lang PureBasic>EnableExplicit
Procedure.b Check_ISIN(*c.Character)
Define count.i=0, Idx.i=1, v.i=0, i.i
Dim s.i(24)
If MemoryStringLength(*c) > 12 : ProcedureReturn #False : EndIf
While *c\c
count+1
If *c\c>='0' And *c\c<='9'
If count<=2 : ProcedureReturn #False : EndIf
s(Idx)= *c\c - '0'
Idx+1
ElseIf *c\c>='A' And *c\c<='Z'
s(Idx)= (*c\c - ('A'-10)) / 10
Idx+1
s(Idx)= (*c\c - ('A'-10)) % 10
Idx+1
Else
ProcedureReturn #False
EndIf
*c + SizeOf(Character)
Wend
For i=Idx-2 To 0 Step -2
If s(i)*2 > 9
v+ s(i)*2 -9
Else
v+ s(i)*2
EndIf
v+s(i+1)
Next
ProcedureReturn Bool(v%10=0)
EndProcedure
Define.s s OpenConsole("Validate_International_Securities_Identification_Number (ISIN)")
If ReadFile(0,"c:\code_pb\rosettacode\data\isin.txt")
While Not Eof(0)
s=ReadString(0)
Print(s+~"\t")
If Check_ISIN(@s) : PrintN("TRUE") : Else : PrintN("FALSE") : EndIf
Wend
CloseFile(0)
EndIf Input()</lang>
- Output:
US0378331005 TRUE US0373831005 FALSE U50378331005 FALSE US03378331005 FALSE AU0000XVGZA3 TRUE AU0000VXGZA3 TRUE FR0000988040 TRUE
Python
<lang python>def check_isin(a):
if len(a) != 12 or not all(c.isalpha() for c in a[:2]) or not all(c.isalnum() for c in a[2:]):
return False
s = "".join(str(int(c, 36)) for c in a)
return 0 == (sum(sum(divmod(2 * (ord(c) - 48), 10)) for c in s[-2::-2]) +
sum(ord(c) - 48 for c in s[::-2])) % 10
- A more readable version
def check_isin_alt(a):
if len(a) != 12:
return False
s = []
for i, c in enumerate(a):
if c.isdigit():
if i < 2:
return False
s.append(ord(c) - 48)
elif c.isupper():
if i == 11:
return False
s += divmod(ord(c) - 55, 10)
else:
return False
v = sum(s[::-2])
for k in s[-2::-2]:
k = 2 * k
v += k - 9 if k > 9 else k
return v % 10 == 0
[check_isin(s) for s in ["US0378331005", "US0373831005", "U50378331005", "US03378331005",
"AU0000XVGZA3", "AU0000VXGZA3", "FR0000988040"]]
- [True, False, False, False, True, True, True]</lang>
Racket
<lang racket>
- lang racket
- convert a base36 character (#\0 - #\Z) to its equivalent
- in base 10 as a string ("0" - "35")
(define (base36-char->base10-string c)
(let ([char-int (char->integer (char-upcase c))]
[zero-int (char->integer #\0)]
[nine-int (char->integer #\9)]
[A-int (char->integer #\A)]
[Z-int (char->integer #\Z)])
(cond [(and (>= char-int zero-int) (<= char-int nine-int)) (~a c)]
[(and (>= char-int A-int) (<= char-int Z-int)) (~a (+ (- char-int A-int) 10))]
[else null])))
- substitute equivalent base 10 numbers for base 36 characters in string
- this is a character-by-character substitution not a conversion
- of a base36 number to a base10 number
(define (base36-string-characters->base10-string-characters s)
(for/fold ([joined ""])
([tenstr (map base36-char->base10-string (string->list (string-upcase s)))])
(values (string-append joined tenstr))))
- This uses the Racket Luhn solution
(define [isin-test? s]
(let ([RE (pregexp "^[A-Z]{2}[A-Z0-9]{9}[0-9]{1}$")])
(and
(regexp-match? RE s)
(luhn-test (string->number (base36-string-characters->base10-string-characters s))))))
(define test-cases '("US0378331005" "US0373831005" "U50378331005" "US03378331005" "AU0000XVGZA3" "AU0000VXGZA3" "FR0000988040"))
(map isin-test? test-cases)
- -> '(#t #f #f #f #t #t #t)
</lang>
- Output:
'(#t #f #f #f #t #t #t)
REXX
<lang rexx>/*REXX program validates the checksum digit for an International Securities ID number.*/ parse arg z /*obtain optional ISINs from the C.L.*/ if z= then z= "US0378331005 US0373831005 U50378331005 US03378331005 AU0000XVGZA3" ,
'AU0000VXGZA3 FR0000988040' /* [↑] use the default list of ISINs.*/
/* [↓] process all specified ISINs.*/
do n=1 for words(z); x=word(z, n); y= x /*obtain an ISIN from the Z list. */
$= /* [↓] construct list of ISIN digits. */
do k=1 for length(x); _= substr(x,k,1) /*the ISIN may contain alphabetic chars*/
p= pos(_, 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ) /*X must contain A──►Z, 0──►9.*/
if p==0 then y= /*trigger "not" valid below.*/
else $= $ || p-1 /*convert X string (base 36 ──► dec).*/
end /*k*/ /* [↑] convert alphabetic ──► digits.*/
@= /*placeholder for the "not" in message.*/
if length(y)\==12 then @= "not" /*see if the ISIN is exactly 12 chars. */
if \datatype( left(x,2),'U') then @= "not" /* " " " " 1st 2 chars cap. let.*/
if \datatype(right(x,1),'W') then @= "not" /* " " " " last char not a digit*/
if @== then if \luhn($) then @= "not" /* " " " " passed the Luhn test.*/
say right(x, 30) right(@, 5) "valid" /*display the yea or nay message.*/
end /*n*/ /* [↑] 1st 3 IFs could've been combined*/
exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ Luhn: procedure; parse arg x; $= 0 /*get credit card number; zero $ sum. */
y= reverse( left(0, length(x) // 2)x) /*add leading zero if needed, & reverse*/
do j=1 to length(y)-1 by 2; _= 2 * substr(y, j+1, 1)
$= $ + substr(y, j, 1) + left(_, 1) + substr(_, 2 , 1, 0)
end /*j*/ /* [↑] sum the odd and even digits.*/
return right($, 1)==0 /*return "1" if number passed Luhn test*/</lang>
- output when using the default inputs:
US0378331005 valid
US0373831005 not valid
U50378331005 not valid
US03378331005 not valid
AU0000XVGZA3 valid
AU0000VXGZA3 valid
FR0000988040 valid
Ring
<lang ring>
- Project : Validate International Securities Identification Number
decimals(0)
test = ["US0378331005",
"US0373831005",
"U50378331005",
"US03378331005",
"AU0000XVGZA3",
"AU0000VXGZA3",
"FR0000988040"]
for n = 1 to len(test)
testold = test[n]
ascii1 = ascii(left(test[n],1))
ascii2 = ascii(substr(test[n],2,1))
if len(test[n]) != 12 or (ascii1 < 65 or ascii1 > 90) or (ascii2 < 65 or ascii2 > 90)
see test[n] + " -> Invalid" + nl
loop
ok
for m = 1 to len(test[n])
if ascii(test[n][m]) > 64 and ascii(test[n][m]) < 91
asc = ascii(test[n][m]) - 55
test[n] = left(test[n],m-1) + string(asc) + right(test[n],len(test[n])-m)
ok
next
see testold + " -> " + cardtest(test[n]) + nl
next
func cardtest(numstr)
revstring = revstr(numstr)
s1 = revodd(revstring)
s2 = reveven(revstring)
s3 =right(string(s1+s2), 1)
if s3 = "0"
return "Valid"
else
return "Invalid"
ok
func revstr(str)
strnew = ""
for nr = len(str) to 1 step -1
strnew = strnew + str[nr]
next
return strnew
func revodd(str)
strnew = ""
for nr = 1 to len(str) step 2
strnew = strnew + str[nr]
next
sumodd = 0
for p = 1 to len(strnew)
sumodd = sumodd + number(strnew[p])
next
return sumodd
func reveven(str)
strnew = ""
for nr = 2 to len(str) step 2
strnew = strnew + str[nr]
next
lsteven = []
for p = 1 to len(strnew)
add(lsteven, string(2*number(strnew[p])))
next
arreven = list(len(lsteven))
for q = 1 to len(lsteven)
sum = 0
for w = 1 to len(lsteven[q])
sum = sum + lsteven[q][w]
next
arreven[q] = sum
next
sumarr = 0
for x = 1 to len(arreven)
sumarr = sumarr + arreven[x]
next
return sumarr
</lang> Output:
US0378331005 -> Valid US0373831005 -> Invalid U50378331005 -> Invalid US03378331005 -> Invalid AU0000XVGZA3 -> Valid AU0000VXGZA3 -> Valid FR0000988040 -> Valid
Ruby
Using a pre-existing luhn method: <lang ruby>RE = /\A[A-Z]{2}[A-Z0-9]{9}[0-9]{1}\z/
def valid_isin?(str)
return false unless str =~ RE
luhn(str.chars.map{|c| c.to_i(36)}.join)
end
p %w(US0378331005 US0373831005 U50378331005 US03378331005 AU0000XVGZA3 AU0000VXGZA3 FR0000988040).map{|tc| valid_isin?(tc) }
- => [true, false, false, false, true, true, true]</lang>
Rust
<lang Rust>extern crate luhn_cc;
use luhn_cc::compute_luhn;
fn main() {
assert_eq!(validate_isin("US0378331005"), true);
assert_eq!(validate_isin("US0373831005"), false);
assert_eq!(validate_isin("U50378331005"), false);
assert_eq!(validate_isin("US03378331005"), false);
assert_eq!(validate_isin("AU0000XVGZA3"), true);
assert_eq!(validate_isin("AU0000VXGZA3"), true);
assert_eq!(validate_isin("FR0000988040"), true);
}
fn validate_isin(isin: &str) -> bool {
// Preliminary checks to avoid working on non-ASCII stuff
if !isin.chars().all(|x| x.is_alphanumeric()) || isin.len() != 12 {
return false;
}
if !isin[..2].chars().all(|x| x.is_alphabetic())
|| !isin[2..12].chars().all(|x| x.is_alphanumeric())
|| !isin.chars().last().unwrap().is_numeric()
{
return false;
}
// Converts the alphanumeric string in a numeric-only string let bytes = isin.as_bytes();
let s2 = bytes.iter()
.flat_map(|&c| {
if c.is_ascii_digit() {
vec![c]
}
else {
(c + 10 - ('A' as u8)).to_string().into_bytes()
}
}).collect::<Vec<u8>>();
let string = std::str::from_utf8(&s2).unwrap(); let number = string.parse::<usize>().unwrap();
return compute_luhn(number);
} </lang>
SAS
<lang sas>data test; length isin $20 ok $1; input isin; keep isin ok; array s{24}; link isin; return; isin: ok="N"; n=length(isin); if n=12 then do;
j=0;
do i=1 to n;
k=rank(substr(isin,i,1));
if k>=48 & k<=57 then do;
if i<3 then return;
j+1;
s{j}=k-48;
end;
else if k>=65 & k<=90 then do;
if i=12 then return;
k+-55;
j+1;
s{j}=int(k/10);
j+1;
s{j}=mod(k,10);
end;
else return;
end;
v=sum(of s{*});
do i=j-1 to 1 by -2;
v+s{i}-9*(s{i}>4);
end;
if mod(v,10)=0 then ok="Y"; end; return; cards; US0378331005 US0373831005 U50378331005 US03378331005 AU0000XVGZA3 AU0000VXGZA3 FR0000988040
run;</lang>
Scala
- Output:
Best seen running in your browser either by ScalaFiddle (ES aka JavaScript, non JVM) or Scastie (remote JVM).
<lang Scala>object Isin extends App {
val isins = Seq("US0378331005", "US0373831005", "U50378331005",
"US03378331005", "AU0000XVGZA3","AU0000VXGZA3", "FR0000988040")
private def ISINtest(isin: String): Boolean = {
val isin0 = isin.trim.toUpperCase
def luhnTestS(number: String): Boolean = {
def luhnTestN(digits: Seq[Int]): Boolean = {
def checksum(digits: Seq[Int]): Int = {
digits.reverse.zipWithIndex
.foldLeft(0) {
case (sum, (digit, i)) =>
if (i % 2 == 0) sum + digit
else sum + (digit * 2) / 10 + (digit * 2) % 10
} % 10
}
checksum(digits) == 0
}
luhnTestN(number.map { c =>
assert(c.isDigit, s"$number has a non-digit error")
c.asDigit
})
}
if (!isin0.matches("^[A-Z]{2}[A-Z0-9]{9}\\d$")) false
else {
val sb = new StringBuilder
for (c <- isin0.substring(0, 12)) sb.append(Character.digit(c, 36))
luhnTestS(sb.toString)
}
}
isins.foreach(isin => println(f"$isin is ${if (ISINtest(isin)) "" else "not"}%s valid"))
}</lang>
SQL PL
version 9.7 or higher.
With SQL PL: <lang sql pl> --#SET TERMINATOR @
SET SERVEROUTPUT ON @
CREATE OR REPLACE FUNCTION VALIDATE_ISIN (
IN IDENTIFIER VARCHAR(12) ) RETURNS SMALLINT -- ) RETURNS BOOLEAN BEGIN DECLARE CHECKSUM_FUNC CHAR(1); DECLARE CONVERTED VARCHAR(24); DECLARE I SMALLINT; DECLARE LENGTH SMALLINT; DECLARE RET SMALLINT DEFAULT 1; --DECLARE RET BOOLEAN DEFAULT FALSE; DECLARE CHAR_AT CHAR(1); DECLARE INVALID_CHAR CONDITION FOR SQLSTATE 'ISIN1';
SET CHAR_AT = SUBSTR(IDENTIFIER, 1, 1); IF (ASCII(CHAR_AT) < 65 OR 90 < ASCII(CHAR_AT)) THEN SIGNAL INVALID_CHAR SET MESSAGE_TEXT = 'Country code with invalid characters'; END IF; SET CHAR_AT = SUBSTR(IDENTIFIER, 2, 1); IF (ASCII(CHAR_AT) < 65 OR 90 < ASCII(CHAR_AT)) THEN SIGNAL INVALID_CHAR SET MESSAGE_TEXT = 'Country code with invalid characters'; END IF;
-- Convert letters to numbers. SET I = 1; SET CONVERTED = ; SET LENGTH = LENGTH(IDENTIFIER); WHILE (I <= LENGTH) DO SET CHAR_AT = SUBSTR(IDENTIFIER, I, 1); IF (48 <= ASCII(CHAR_AT) AND ASCII(CHAR_AT) <= 57) THEN SET CONVERTED = CONVERTED || CHAR_AT; ELSE SET CONVERTED = CONVERTED || (ASCII(CHAR_AT) - 55); END IF; SET I = I + 1; END WHILE;
CALL DBMS_OUTPUT.PUT_LINE(CONVERTED); -- This function is implemented in Rosetta code. SET CHECKSUM_FUNC = LUHN_TEST(CONVERTED); IF (CHECKSUM_FUNC = 0) THEN SET RET = 0; --SET RET = TRUE; END IF;
RETURN RET; END @
</lang> Output:
db2 -td@
db2 => BEGIN
...
db2 (cont.) => END @
DB20000I The SQL command completed successfully.
db2 => VALUES VALIDATE_ISIN('US0378331005')@
1
------
0
1 record(s) selected.
30280378331005
It is a valid number 27+23=50
db2 => VALUES VALIDATE_ISIN('US0373831005')@
1
------
1
1 record(s) selected.
30280373831005
It is NOT a valid number 22+24=46
db2 => VALUES VALIDATE_ISIN('U50378331005')@
1
------
SQL0438N Application raised error or warning with diagnostic text: "Country
code with invalid characters". SQLSTATE=ISIN1
db2 => VALUES VALIDATE_ISIN('U503378331005')@
1
------
SQL0433N Value "U503378331005" is too long. SQLSTATE=22001
db2 => VALUES VALIDATE_ISIN('AU0000XVGZA3')@
1
------
0
1 record(s) selected.
1030000033311635103
It is a valid number 18+12=30
db2 => VALUES VALIDATE_ISIN('AU0000VXGZA3')@
1
------
0
1 record(s) selected.
1030000031331635103
It is a valid number 18+12=30
db2 => VALUES VALIDATE_ISIN('FR0000988040')@
1
------
0
1 record(s) selected.
15270000988040
It is a valid number 20+30=50
Tcl
<lang Tcl>package require Tcl 8.6 ;# mostly needed for [assert]. Substitute a simpler one or a NOP if required.</lang> A proc like assert is always good to have around. This one tries to report values used in its expression using subst: <lang Tcl>proc assert {expr} { ;# for "static" assertions that throw nice errors
if {![uplevel 1 [list expr $expr]]} {
set msg "{$expr}"
catch {append msg " {[uplevel 1 [list subst -noc $expr]]}"}
tailcall throw {ASSERT ERROR} $msg
}
}</lang> isin itself is a simple package. We compute the alphabet when the package is loaded in _init, because that's more fun than typing out the table: <lang Tcl>namespace eval isin {
proc _init {} { ;# sets up the map used on every call
variable map
set alphabet abcdefghijklmnopqrstuvwxyz
set n 9
lmap c [split $alphabet ""] {
lappend map $c [incr n]
}
}
_init
proc normalize {isin} {
variable map
string map $map [string tolower [string trim $isin]]
}
# copied from "Luhn test of credit card numbers"
# included here for ease of testing, and because it is short
proc luhn digitString {
if {[regexp {[^0-9]} $digitString]} {error "not a number"}
set sum 0
set flip 1
foreach ch [lreverse [split $digitString {}]] {
incr sum [lindex {
{0 1 2 3 4 5 6 7 8 9}
{0 2 4 6 8 1 3 5 7 9}
} [expr {[incr flip] & 1}] $ch]
}
return [expr {($sum % 10) == 0}]
}
proc validate {isin} {
if {![regexp {^[A-Z]{2}[A-Z0-9]{9}[0-9]$} $isin]} {return false}
luhn [normalize $isin]
}
}</lang> To run the test suite, we use the tcltest framework included with Tcl: <lang Tcl>package require tcltest
tcltest::test isin-1 "Test isin validation" -body {
foreach {isin ok} {
US0378331005 yes
US0373831005 no
U50378331005 no
US03378331005 no
AU0000XVGZA3 yes
AU0000VXGZA3 yes
FR0000988040 yes
} {
if {$ok} {
assert {[isin::validate $isin]}
} else {
assert {![isin::validate $isin]}
}
}
return ok
} -result ok</lang>
Transact-SQL
<lang Transact-SQL> CREATE FUNCTION dbo._ISINCheck( @strISIN VarChar(40) ) RETURNS bit AS BEGIN --*** Test an ISIN code and return 1 if it is valid, 0 if invalid. DECLARE @bValid bit;
SET @bValid = CASE WHEN @strISIN LIKE '[A-Z][A-Z][A-Z,0-9][A-Z,0-9][A-Z,0-9][A-Z,0-9][A-Z,0-9][A-Z,0-9][A-Z,0-9][A-Z,0-9][A-Z,0-9][0-9]' THEN 1 ELSE 0 END IF @bValid = 1 BEGIN DECLARE @strTest VarChar(40) = ; DECLARE @strAdd VarChar(2); DECLARE @p INT = 0; WHILE @p < LEN(@strISIN) BEGIN SET @p = @p+1; SET @strAdd = SUBSTRING(@strISIN,@p,1); IF @strAdd LIKE '[A-Z]' SET @strAdd = CONVERT(VarChar(2),ASCII(UPPER(@strAdd))-55); SET @strTest = @strTest + @strAdd; END;
-- Proceed with Luhn test DECLARE @strLuhn VarChar(40) = REVERSE(@strTest); -- usage: set once, never changed DECLARE @strS2Values VarChar(10) = '0246813579'; -- constant: maps digits to their S2 summed values SET @p = 0; -- reset loop counter DECLARE @intValue INT; DECLARE @intSum INT = 0; -- loop through the reversed string, get the value (even-positioned digits are mapped) and add it to @intSum WHILE @p < LEN(@strLuhn) BEGIN SET @p = @p+1; SET @intValue = CONVERT(INT, SUBSTRING(@strLuhn,@p,1) ) -- value of the digit at position @p in the string IF @p % 2 = 0 SET @intValue = CONVERT(INT,SUBSTRING(@strS2Values,@intValue+1,1)) SET @intSum = @intSum + @intValue END -- If the of the digits' mapped values ends in 0 (modulo 10 = 0) then the Luhn test succeeds SET @bValid = CASE WHEN @intSum % 10 = 0 THEN 1 ELSE 0 END END;
RETURN @bValid END </lang> Testing <lang Transact-SQL> -- Testing. The following tests all pass.
- WITH ISIN_Tests AS
( SELECT 'US0378331005' AS ISIN, 1 Expected
UNION SELECT 'US0373831005',0 UNION SELECT 'U50378331005',0 UNION SELECT 'US03378331005',0 UNION SELECT 'AU0000XVGZA3',1 UNION SELECT 'AU0000VXGZA3',1 UNION SELECT 'FR0000988040',1 UNION SELECT '0___garbage',0 UNION SELECT ,0
) SELECT ISIN, Expected, dbo._ISINCheck(ISIN) AS TestResult FROM ISIN_Tests ORDER BY ISIN </lang>
VBScript
<lang vb>' Validate International Securities Identification Number - 03/03/2019
buf=buf&test("US0378331005")&vbCrLf buf=buf&test("US0373831005")&vbCrLf buf=buf&test("U50378331005")&vbCrLf buf=buf&test("US03378331005")&vbCrLf buf=buf&test("AU0000XVGZA3")&vbCrLf buf=buf&test("AU0000VXGZA3")&vbCrLf buf=buf&test("FR0000988040")&vbCrLf msgbox buf,,"Validate International Securities Identification Number"
function test(cc) dim err,c,r,s,i1,i2 if len(cc)=12 then for i=1 to len(cc) p=instr("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ",mid(cc,i,1)) if p<>0 then c=c&(p-1) else err=1 next 'i for i=1 to 2 if instr("ABCDEFGHIJKLMNOPQRSTUVWXYZ",mid(cc,i,1))=0 then err=1 next 'i if err=0 then for i=len(c) to 1 step -1 r=r&mid(c,i,1) next 'i for i=1 to len(r) step 2 i1=i1+cint(mid(r,i,1)) next 'i for i=2 to len(r) step 2 ii=cint(mid(r,i,1))*2 if ii>=10 then ii=ii-9 i2=i2+ii next 'i s=cstr(i1+i2) if mid(s,len(s),1)="0" then msg="valid" else msg="invalid ??1" end if else msg="invalid ??2" end if else msg="invalid ??3" end if test=cc&" "&msg end function 'test </lang>
- Output:
US0378331005 valid US0373831005 invalid ??1 U50378331005 invalid ??2 US03378331005 invalid ??3 AU0000XVGZA3 valid AU0000VXGZA3 valid FR0000988040 valid
Visual Basic
Calls LuhnCheckPassed() function described at Luhn_test_of_credit_card_numbers#Visual_Basic <lang vb>Function IsValidISIN(ByVal ISIN As String) As Boolean Dim s As String, c As String Dim i As Long
If Len(ISIN) = 12 Then
For i = 1 To Len(ISIN)
c = UCase$(Mid(ISIN, i, 1))
Select Case c
Case "A" To "Z"
If i = 12 Then Exit Function
s = s & CStr(Asc(c) - 55)
Case "0" To "9"
If i < 3 Then Exit Function
s = s & c
Case Else
Exit Function
End Select
Next i
IsValidISIN = LuhnCheckPassed(s)
End If
End Function</lang> Test: <lang vb>Sub Main()
Debug.Assert IsValidISIN("US0378331005")
Debug.Assert Not IsValidISIN("US0373831005")
Debug.Assert Not IsValidISIN("U50378331005")
Debug.Assert Not IsValidISIN("US03378331005")
Debug.Assert IsValidISIN("AU0000XVGZA3")
Debug.Assert IsValidISIN("AU0000VXGZA3")
Debug.Assert IsValidISIN("FR0000988040")
Debug.Assert Not IsValidISIN("FR000098804O")
End Sub</lang>
Yabasic
<lang Yabasic>sub luhntest(cardnr$)
local i, j, s1, s2, l
cardnr$ = Trim$(cardnr$) // remove spaces
l = Len(cardnr$)
// sum odd numbers
For i = l To 1 Step -2
s1 = s1 + (asc(mid$(cardnr$, i, 1)) - Asc("0"))
Next
// sum even numbers
For i = l-1 To 1 Step -2
j = asc(mid$(cardnr$, i, 1)) - Asc("0")
j = j * 2
If j > 9 j = mod(j, 10) + 1
s2 = s2 + j
Next
return mod(s1 + s2, 10) = 0
End sub
// ------=< MAIN >=-----
data "US0378331005", "US0373831005", "U50378331005", "US03378331005", "AU0000XVGZA3", "AU0000VXGZA3", "FR0000988040", ""
do
read test_item$
if test_item$ = "" break
l = Len(test_item$)
If l <> 12 Then
Print test_item$, " Invalid, length <> 12 char."
Continue
End If
c1$ = mid$(test_item$, 1, 1) : c2$ = mid$(test_item$, 2, 1)
If c1$ < "A" Or c1$ > "Z" or c2$ < "A" or c2$ > "Z" Then
Print test_item$, " Invalid, number needs to start with 2 characters"
Continue
End If
test_str$ = ""
For n = 1 To l
x = asc(mid$(test_item$, n, 1)) - Asc("0")
// if is a letter we to correct for that
If x > 9 x = x - 7
If x < 10 Then
test_str$ = test_str$ + Str$(x)
Else // two digest number
test_str$ = test_str$ + Str$(int(x / 10)) + Str$(mod(x, 10))
End If
Next
Print test_item$;
if luhntest(test_str$) then print " Valid" else print " Invalid, checksum error" end if
loop </lang>
zkl
Uses the luhn test from Luhn_test_of_credit_card_numbers#zkl (copied here as it is short). <lang zkl>fcn validateISIN(isin){
RegExp(String("^","[A-Z]"*2,"[A-Z0-9]"*9,"[0-9]$")).matches(isin) and
luhnTest(isin.split("").apply("toInt",36).concat().toInt())
} fcn luhnTest(n){
0 == (n.split().reverse().reduce(fcn(s,n,clk){
s + if(clk.inc()%2) n else 2*n%10 + n/5 },0,Ref(1)) %10)
}</lang> <lang zkl>println(" ISIN Valid?"); foreach isin in (T("US0378331005","US0373831005","U50378331005", "US03378331005","AU0000XVGZA3","AU0000VXGZA3","FR0000988040")){
println(isin," --> ",validateISIN(isin));
}</lang>
- Output:
ISIN Valid? US0378331005 --> True US0373831005 --> False U50378331005 --> False US03378331005 --> False AU0000XVGZA3 --> True AU0000VXGZA3 --> True FR0000988040 --> True
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