Selectively replace multiple instances of a character within a string: Difference between revisions
Selectively replace multiple instances of a character within a string (view source)
Revision as of 10:51, 4 February 2024
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{{Template:Strings}}
<br>
=={{header|11l}}==
{{trans|Python}}
<syntaxhighlight lang="11l">V rep = [‘a’ = [1 = ‘A’, 2 = ‘B’, 4 = ‘C’, 5 = ‘D’], ‘b’ = [1 = ‘E’], ‘r’ = [2 = ‘F’]]
F trstring(oldstring, repdict)
DefaultDict[Char, Int] seen
V newchars = ‘’
L(c) oldstring
V i = ++seen[c]
newchars ‘’= I c C repdict & i C repdict[c] {repdict[c][i]} E c
R newchars
print(‘abracadabra -> ’trstring(‘abracadabra’, rep))</syntaxhighlight>
{{out}}
<pre>
abracadabra -> AErBcadCbFD
</pre>
=={{header|ALGOL 68}}==
Line 113 ⟶ 133:
{{out}}
<pre>AErBcadCbFD</pre>
=={{header|C}}==
<syntaxhighlight lang="c">
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void) {
const char string[] = "abracadabra";
char *replaced = malloc(sizeof(string));
strcpy(replaced, string);
// Null terminated replacement character arrays
const char *aRep = "ABaCD";
const char *bRep = "E";
const char *rRep = "rF";
for (char *c = replaced; *c; ++c) {
switch (*c) {
case 'a':
if (*aRep)
*c = *aRep++;
break;
case 'b':
if (*bRep)
*c = *bRep++;
break;
case 'r':
if (*rRep)
*c = *rRep++;
break;
}
}
printf("%s\n", replaced);
free(replaced);
return 0;
}
</syntaxhighlight>
{{out}}
<pre>
AErBcadCbFD
</pre>
=={{header|C++}}==
Line 143 ⟶ 208:
AErBcadCbFD
</pre>
=={{header|Delphi}}==
{{works with|Delphi|6.0}}
{{libheader|SysUtils,StdCtrls}}
<syntaxhighlight lang="Delphi">
var TestStr: string = 'abracadabra';
function FindNthChar(C: char; S: string; N: integer): integer;
{Routine to find the Nth version of C, string S}
begin
for Result:=1 to Length(S) do
if S[Result]=C then
begin
Dec(N);
if N<=0 then exit;
end;
Result:=-1;
end;
procedure ReplaceNthChar(COld,CNew: char; var S: string; N: integer);
{Find and replace the Nth version COld with CNew}
var Inx: integer;
begin
Inx:=FindNthChar(COld,S,N);
if Inx<1 then exit;
S[Inx]:=CNew;
end;
procedure SelectivelyReplaceChars(Memo: TMemo);
var I: integer;
begin
Memo.Lines.Add('Before: '+TestStr);
{Do the replacement toward the end of string first}
ReplaceNthChar('a','D',TestStr,5);
ReplaceNthChar('a','C',TestStr,4);
ReplaceNthChar('a','B',TestStr,2);
ReplaceNthChar('r','F',TestStr,2);
ReplaceNthChar('a','A',TestStr,1);
ReplaceNthChar('b','E',TestStr,1);
Memo.Lines.Add('After: '+TestStr);
end;
</syntaxhighlight>
{{out}}
<pre>
Before: AErBcadCbFD
After: AErBcAdCEFD
Elapsed Time: 1.749 ms.
</pre>
=={{header|EMal}}==
Line 348 ⟶ 470:
'aABaCD' chg 'bEb' chg 'rrF' chg 'abracadabra'
AErBcadCbFD</syntaxhighlight>
=={{header|Java}}==
{{trans|JavaScript}}
Here's an example translated from JavaScript.
<syntaxhighlight lang="java">
int findNth(String s, char c, int n) {
if (n == 1) return s.indexOf(c);
return s.indexOf(c, findNth(s, c, n - 1) + 1);
}
String selectiveReplace(String s, Set... ops) {
char[] chars = s.toCharArray();
for (Set set : ops)
chars[findNth(s, set.old, set.n)] = set.rep;
return new String(chars);
}
record Set(int n, char old, char rep) { }
</syntaxhighlight>
<syntaxhighlight lang="java">
selectiveReplace("abracadabra",
new Set(1, 'a', 'A'),
new Set(2, 'a', 'B'),
new Set(4, 'a', 'C'),
new Set(5, 'a', 'D'),
new Set(1, 'b', 'E'),
new Set(2, 'r', 'F'));
</syntaxhighlight>
{{out}}
<pre>AErBcadCbFD</pre>
=={{header|JavaScript}}==
Line 618 ⟶ 772:
(AErBcadCbFD)
</syntaxhighlight>
=={{header|Nim}}==
<syntaxhighlight lang="Nim">import std/tables
type
# Table of replacements for a character.
Replacements = Table[int, char]
# Table mapping characters to their replacement table.
ReplacementTable = Table[char, Replacements]
const ReplTable = {'a': {1: 'A', 2: 'B', 4: 'C', 5: 'D'}.toTable,
'b': {1: 'E'}.toTable,
'r': {2: 'F'}.toTable
}.toTable
proc replace(text: string; replTable: ReplacementTable): string =
var counts: Table[char, int] # Follow count of characters.
for c in text:
if c in replTable:
counts.mgetOrPut(c, 0).inc # Update count for this char.
let pos = counts[c]
result.add replTable[c].getOrDefault(pos, c)
else:
result.add c
echo replace("abracadabra", ReplTable)
</syntaxhighlight>
{{out}}
<pre>AErBcadCbFD
</pre>
=={{header|Perl}}==
Line 882 ⟶ 1,067:
caarabadrab -> cABraECdFDb</pre>
=={{header|RPL}}==
The character "-" in the rule string means that no replacement should be made for the occurrence concerned. Any other character can be chosen by modifying the code appropriately.
Due to the use of <code>INCR</code> and <code>REPL</code> instructions, this program will only work directly on HP48 compatible RPL versions. HP28 users must have programmed their own version of these instructions.
{| class="wikitable"
! RPL code
! Comment
|-
|
≪ 0 → car rule occ
≪ 1 OVER SIZE '''FOR''' j
'''IF''' DUP j DUP SUB car == '''THEN'''
rule 'occ' INCR DUP SUB
'''IF''' DUP "-" == '''THEN''' DROP '''ELSE''' j SWAP REPL '''END'''
'''END NEXT'''
≫ ≫ ''''REPLR'''' STO
|
'''REPLR''' ''( "string" "character" "rule" -- "string" ) ''
loop for j = 1 to string length
if string[j] == character
get todo = rule[++occ]
replace if todo is different from "-"
end if end loop
return string
|}
{{in}}
<pre>
"abracadabra"
≪ "a" "AB-CD" REPLR "b" "E" REPLR "r" "-F" REPLR ≫ EVAL
</pre>
{{out}}
<pre>
1: "AErBcadCbFD"
</pre>
=={{header|Ruby}}==
<syntaxhighlight lang="ruby">str = "abracadabra"
rules = [
["a", 1, "A"],
["a", 2, "B"],
["a", 4, "C"],
["a", 5, "D"],
["b", 1, "E"],
["r", 2, "F"]]
indices = Hash.new{[]}
str.each_char.with_index{|c, i| indices[c] <<= i}
rules.each{|char, i, to| str[indices[char][i-1]] = to}
p str</syntaxhighlight>
{{out}}
<pre>"AErBcadCbFD"
</pre>
=={{header|sed}}==
<syntaxhighlight lang="sed">s/a\([^a]*\)a\([^a]*a[^a]*\)a\([^a]*\)a/A\1B\2C\3D/
Line 929 ⟶ 1,168:
{{libheader|Wren-regex}}
Not particularly succinct but, thanks to a recently added library method, better than it would have been :)
<syntaxhighlight lang="
import "./str" for Str
Line 948 ⟶ 1,187:
Alternatively, using regular expressions (embedded script) producing output as before.
<syntaxhighlight lang="
var s = "abracadabra"
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