Integer comparison: Difference between revisions

From Rosetta Code
Content added Content deleted
(Added REBOL example.)
Line 886: Line 886:
a: ask "First integer? " b: ask "Second integer? "
a: ask "First integer? " b: ask "Second integer? "


relation: [
relation: [a < b "less than" a = b "equal to" a > b "greater than"]
a < b "less than"
a = b "equal to"
a > b "greater than"
]
print [a "is" case relation b]
print [a "is" case relation b]
</lang>
</lang>

Revision as of 07:50, 4 December 2009

Task
Integer comparison
You are encouraged to solve this task according to the task description, using any language you may know.

Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.

You may see other such operations in the Basic Data Operations category, or:

Integer Operations
Arithmetic | Comparison

Boolean Operations
Bitwise | Logical

String Operations
Concatenation | Interpolation | Comparison | Matching

Memory Operations
Pointers & references | Addresses

Get two integers from the user, and then output if the first one is less, equal or greater than the other. Test the condition for each case separately, so that all three comparison operators are used in the code.

Ada

<lang ada>with Ada.Text_IO; use Ada.Text_IO; with Ada.Integer_Text_IO; use Ada.Integer_Text_Io;

procedure Compare_Ints is 

  A, B : Integer;

begin 

  Get(Item => A);
  Get(Item => B);

  -- Test for equality
  if A = B then
     Put_Line("A equals B");
  end if;

  -- Test For Less Than
  if A < B then
     Put_Line("A is less than B");
  end if;

  -- Test For Greater Than
  if A > B then
     Put_Line("A is greater than B");
  end if;

end Compare_Ints;</lang>

ALGOL 68

Works with: ALGOL 68 version Standard - no extensions to language used

Note: the standard includes the characters "≤", "≥" and "≠". These appear in the character sets wp:GOST 10859, ISOtech and IBM's wp:EBCDIC e.g. code page 293, and in extended ASCII code pages 910 & 910

Works with: ALGOL 68G version Any - tested with release mk15-0.8b.fc9.i386
Works with: ELLA ALGOL 68 version Any (with appropriate job cards) - tested with release 1.8.8d.fc9.i386

The current distribution of both ALGOL 68G and ELLA ALGOL 68 compilers only allow wp:ASCII characters (ASCII has neither "≤", "≥" nor "≠" characters). <lang algol68>main: ( 

 INT a, b;
 read((a, space, b, new line));

 IF a <= b OR a LE b # OR a ≤ b # THEN
   print((a," is less or equal to ", b, new line))
 FI;
 IF a < b OR a LT b THEN
   print((a," is less than ", b, new line))
 ELIF a = b OR a EQ b THEN
   print((a," is equal to ", b, new line))
 ELIF a > b OR a GT b THEN
   print((a," is greater than ", b, new line))
 FI;
 IF a /= b OR a NE b # OR a ≠ b # THEN
   print((a," is not equal to ", b, new line))
 FI;
 IF a >= b OR a GE b # OR a ≥ b # THEN
   print((a," is greater or equal to ", b, new line))
 FI

)</lang> Example output: <lang algol68>+3 is less or equal to +4 

        +3 is less than          +4
        +3 is not equal to          +4</lang>

AutoHotkey

Error checking is performed automatically by attaching UpDowns to each of the Edit controls. UpDown controls always yield an in-range number, even when the user has typed something non-numeric or out-of-range in the Edit control. The default range is 0 to 100. <lang autohotkey>Gui, Add, Edit Gui, Add, UpDown, vVar1 Gui, Add, Edit Gui, Add, UpDown, vVar2 Gui, Add, Button, Default, Submit Gui, Show Return

ButtonSubmit: 

 Gui, Submit, NoHide
 If (Var1 = Var2)
   MsgBox, % Var1 "=" Var2
 Else If (Var1 < Var2)
   MsgBox, % Var1 "<" Var2
 Else If (Var1 > Var2)
   MsgBox, % Var1 ">" Var2

Return

GuiClose: 

 ExitApp</lang>

AWK

<lang awk>/[0-9]* [0-9]*/{ if ($1 == $2) print $1, "is equal to", $2 if ($1 < $2) print $1, "is less than", $2 if ($1 > $2) print $1, "is greater than", $2 }</lang>

BASIC

Works with: QuickBasic version 4.5

<lang qbasic>CLS INPUT "a, b"; a, b 'remember to type the comma when you give the numbers PRINT "a is "; IF a < b THEN PRINT "less than "; IF a = b THEN PRINT "equal to "; IF a > b THEN PRINT "greater than "; PRINT "b"</lang>

Befunge

Befunge only has the greater-than operator (backtick `). The branch commands (underline _ and pipe |) test for zero.

<lang befunge>v v ">" $< >&&"=A",,\:."=B ",,,\: .55+,-:0`| 

                     v  "<" _v#<
  @,+55,," B",,,"A " <  "="  <</lang>

Common Lisp

You can type this directly into a REPL:

<lang lisp>(let ((a (read *standard-input*)) 

     (b (read *standard-input*)))
   (cond
     ((not (numberp a)) (format t "~A is not a number." a))
     ((not (numberp b)) (format t "~A is not a number." b))
     ((< a b) (format t "~A is less than ~A." a b))
     ((> a b) (format t "~A is greater than ~A." a b))
     ((= a b) (format t "~A is equal to ~A." a b))
     (t (format t "Cannot determine relevance between ~A and ~B!" a b)))))</lang>

After hitting enter, the REPL is expecting the two numbers right away. You can enter the two numbers, and the result will print immediately. Alternatively, you can wrap this code in a function definition:

<lang lisp>(defun compare-integers () 

 (let ((a (read *standard-input*))
       (b (read *standard-input*)))
   (cond
     ((not (numberp a)) (format t "~A is not a number." a))
     ((not (numberp b)) (format t "~A is not a number." b))
     ((< a b) (format t "~A is less than ~A." a b))
     ((> a b) (format t "~A is greater than ~A." a b))
     ((= a b) (format t "~A is equal to ~A." a b))
     (t (format t "Cannot determine relevance between ~A and ~B!" a b)))))</lang>

Then, execute the function for better control: 

(compare-integers)

C

<lang c>#include <stdio.h>

int main() { 

 int a, b;
 scanf("%d %d", &a, &b);

 if (a < b)
   printf("%d is less than %d\n", a, b);

 if (a == b)
   printf("%d is equal to %d\n", a, b);

 if (a > b)
   printf("%d is greater than %d\n", a, b);

 return 0;

}</lang>

C++

<lang cpp>#include <iostream> using namespace std;

int main() { 

 int a, b;
 cin >> a >> b;

 // test for less-than
 if (a < b)
   cout << a << " is less than " << b << endl;

 // test for equality
 if (a == b)
   cout << a << " is equal to " << b << endl;

 // test for greater-than
 if (a > b)
   cout << a << " is greater than " << b << endl;

}</lang>

C#

<lang csharp>using System;

class Program { 

   static void Main()
   {
       int a = int.Parse(Console.ReadLine());
       int b = int.Parse(Console.ReadLine());
       if (a < b)
           Console.WriteLine("{0} is less than {1}", a, b);
       if (a == b)
           Console.WriteLine("{0} equals {1}", a, b);
       if (a > b)
           Console.WriteLine("{0} is greater than {1}", a, b);
   }

}</lang>

Clean

<lang clean>import StdEnv

compare a b 

   | a < b = "A is less than B"
   | a > b = "A is more than B"
   | a == b = "A equals B"

Start world 

   # (console, world) = stdio world
     (_, a, console) = freadi console
     (_, b, console) = freadi console
   = compare a b</lang>

D

<lang d>import std.stdio, std.string;

void main() { 

 auto a = readln().atoi(), b = readln().atoi();
 if (a < b)
   writefln(a, " is less than ", b);

 if (a == b)
   writefln(a, " is equal to ", b);

 if (a > b)
   writefln(a, " is greater than ", b);

}</lang>

E

<lang e>def compare(a :int, b :int) { 

 println(if (a < b)        { `$a < $b` } \
         else if (a <=> b) { `$a = $b` } \
         else if (a > b)   { `$a > $b` } \
         else              { `You're calling that an integer?` })

}</lang>

FALSE

Only equals and greater than are available. <lang false>^^ \$@$@$@$@\ >[\$," is greater than "\$,]? \>[\$," is less than "\$,]? =["characters are equal"]?</lang>

Forth

To keep the example simple, the word takes the two numbers from the stack. <lang forth>: compare-integers ( a b -- ) 

  2dup < if ." a is less than b" then
  2dup > if ." a is greater than b" then
       = if ." a is equal to b" then ;</lang>

Fortran

In ALL Fortran versions (including original 1950's era) you could use an "arithmetic IF" statement to compare using subtraction: <lang fortran>program arithif integer a, b

c fortran 77 I/O statements, for simplicity read(*,*) a, b

if ( a - b ) 10, 20, 30 10 write(*,*) a, ' is less than ', b 

  goto 40

20 write(*,*) a, ' is equal to ', b 

  goto 40

30 write(*,*) a, ' is greater than ', b 40 continue

end</lang>

In ANSI FORTRAN 66 or later you could use relational operators (.lt., .gt., .eq., etc.) and unstructured IF statements: <lang fortran>program compare integer a, b c fortran 77 I/O statements, for simplicity read(*,*) a, b

if (a .lt. b) write(*, *) a, ' is less than ', b if (a .eq. b) write(*, *) a, ' is equal to ', b if (a .gt. b) write(*, *) a, ' is greater than ', b end</lang>

In ANSI FORTRAN 77 or later you can use relational operators and structured IF statements: <lang fortran>program compare integer a, b read(*,*) a, b

if (a .lt. b) then 

 write(*, *) a, ' is less than ', b

else if (a .eq. b) then 

 write(*, *) a, ' is equal to ', b

else if (a .gt. b) then 

 write(*, *) a, ' is greater than ', b

end if

end</lang>

In ISO Fortran 90 or later you can use symbolic relational operators (<, >, ==, etc.) <lang fortran>program compare integer :: a, b read(*,*) a, b

if (a < b) then 

 write(*, *) a, ' is less than ', b

else if (a == b) then 

 write(*, *) a, ' is equal to ', b

else if (a > b) then 

 write(*, *) a, ' is greater than ', b

end if

end program compare</lang>

F#

<lang fsharp>let compare_ints a b = 

   let r = 
       match a with
       | x when x < b -> -1, printfn "%d is less than %d" x b
       | x when x = b -> 0,  printfn "%d is equal to %d" x b
       | x when x > b -> 1,  printfn "%d is greater than %d" x b
       | x -> 0, printf "default condition (not reached)"
   fst r</lang>

Groovy

Relational Operators

<lang groovy>def comparison = { a, b -> 

   println "a ? b    = ${a} ? ${b}    = a ${a < b ? '<' : a > b ? '>' : a == b ? '==' : '?'} b"

}</lang>

Program: <lang groovy>comparison(2000,3) comparison(2000,300000) comparison(2000,2000)</lang>

Output: 

a ? b    = 2000 ? 3    = a > b
a ? b    = 2000 ? 300000    = a < b
a ? b    = 2000 ? 2000    = a == b

"Spaceship" (compareTo) Operator

Using spaceship operator and a lookup table: <lang groovy>def comparison = { a, b -> 

   def rels = [ (-1) : '<', 0 : '==', 1 : '>' ]
   println "a ? b    = ${a} ? ${b}    = a ${rels[a <=> b]} b"

}</lang>

Program: <lang groovy>comparison(2000,3) comparison(2000,300000) comparison(2000,2000)</lang>

Output: 

a ? b    = 2000 ? 3    = a > b
a ? b    = 2000 ? 300000    = a < b
a ? b    = 2000 ? 2000    = a == b

Haskell

<lang haskell>myCompare a b 

 | a < b  = "A is less than B"
 | a > b  = "A is greater than B"
 | a == b = "A equals B"

main = do 

 a' <- getLine
 b' <- getLine
 let { a :: Integer; a = read a' }
 let { b :: Integer; b = read b' }
 putStrLn $ myCompare a b</lang>

However, the more idiomatic and less error-prone way to do it in Haskell would be to use a compare function that returns type Ordering, which is either LT, GT, or EQ: <lang haskell>myCompare a b = case compare a b of 

                 LT -> "A is less than B"
                 GT -> "A is greater than B"
                 EQ -> "A equals B"</lang>

J

Comparison is accomplished by the verb compare, which provides logical-numeric output.
Text elaborating the output of compare is provided by cti: <lang j>compare=: < , = , >

cti=: dyad define 

 select  =. ;@#
 English =. ' is less than ';' is equal to ';' is greater than ' 
 x (":@[, (compare select English"_), ":@]) y

)</lang> Examples of use: <lang j> 4 compare 4 0 1 0 

  4 cti 3

4 is greater than 3</lang>

Java

<lang java>import java.io.*;

public class compInt { 

  public static void main(String[] args) {
      try {
          BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

          int nbr1 = Integer.parseInt(in.readLine());
          int nbr2 = Integer.parseInt(in.readLine());

          if(nbr1<nbr2)
              System.out.println(nbr1 + " is less than " + nbr2);

          if(nbr1>nbr2)
               System.out.println(nbr1 + " is greater than " + nbr2);

          if(nbr1==nbr2)
               System.out.println(nbr1 + " is equal to " + nbr2);
      } catch(IOException e) { }
  }

}</lang>

JavaScript

<lang javascript>function compare(a,b) { 

 if (a==b) print(a + " equals " + b);
 if (a < b) print(a + " is less than " + b);
 if (a > b) print(a + " is greater than " + b);

}</lang>

Joy

<lang joy>#!/usr/local/bin/joy.exe DEFINE prompt == "Please enter a number and <Enter>: " putchars; newline == '\n putch; putln == put newline.

stdin # F prompt fgets # S F 10 strtol # A F swap # F A dupd # F A A prompt fgets # S F A A 10 strtol # B F A A popd # B A A dup # B B A A rollup # B A B A [<] [swap put "is less than " putchars putln] [] ifte [=] [swap put "is equal to " putchars putln] [] ifte [>] [swap put "is greater than " putchars putln] [] ifte # B A quit.</lang>

Korn Shell

<lang korn>#!/bin/ksh

  1. tested with ksh93s+

builtin printf

integer a=0 integer b=0

read a?"Enter value of a: " || { print -u2 "Input of a aborted." ; exit 1 ; } read b?"Enter value of b: " || { print -u2 "Input of b aborted." ; exit 1 ; }

if (( a < b )) ; then 

   printf "%d is less than %d\n" a b

fi if (( a == b )) ; then 

   printf "%d is equal to %d\n" a b

fi if (( a > b )) ; then 

   printf "%d is greater than %d\n" a b

fi

exit 0</lang>

<lang logo>to compare :a :b 

 if :a = :b [(print :a [equals] :b)]
 if :a < :b [(print :a [is less than] :b)]
 if :a > :b [(print :a [is greater than] :b)]

end</lang> Each infix operator has prefix synonyms (equalp, equal?, lessp, less?, greaterp, greater?), where the 'p' stands for "predicate" as in Lisp.

LSE64

<lang lse64>over : 2 pick 2dup : over over

compare : 2dup = then " equals" compare : 2dup < then " is less than" compare : 2dup > then " is more than"

show : compare rot , sp ,t sp , nl</lang>

Mathematica

<lang Mathematica>a=Input["Give me the value for a please!"]; b=Input["Give me the value for b please!"]; If[a==b,Print["a equals b"]] If[a>b,Print["a is bigger than b"]] If[a<b,Print["b is bigger than a"]]</lang>

MAXScript

<lang maxscript>a = getKBValue prompt:"Enter value of a:" b = getKBValue prompt:"Enter value of b:" if a < b then print "a is less then b" else if a > b then print "a is greater then b" else if a == b then print "a is equal to b"</lang>

Metafont

<lang metafont>message "integer 1: "; a1 := scantokens readstring; message "integer 2: "; a2 := scantokens readstring; if a1 < a2: 

 message decimal a1 & " is less than " & decimal a2

elseif a1 > a2: 

 message decimal a1 & " is greater than " & decimal a2

elseif a1 = a2: 

 message decimal a1 & " is equal to " & decimal a2

fi; end</lang>

MMIX

Some simple error checking is included. <lang mmix>// main registers p IS $255 % pointer pp GREG % backup for p A GREG % first int B GREG % second int

// arg registers argc IS $0 argv IS $1

LOC Data_Segment GREG @ ERR BYTE "Wrong number of arguments",#a,0 ILLH BYTE "Argument -> ",0 ILLT BYTE " <- contains an illegal character",#a,0 LT BYTE "A is less than B",#a,0 EQ BYTE "A equals B",#a,0 GT BYTE "A is greater than B",#a,0

LOC #1000 GREG @ // call: p points to the start of a 0-terminated numeric string // leading chars + and - are allowed // reg $72 0 if negative int // reg $73 gen. purpose // return: reg $70 contains integer value readInt XOR $70,$70,$70 % reset result reg: N=0. LDA pp,p % remember &p LDBU $72,p CMP $73,$72,'+' % ignore '+' BZ $73,2F CMP $72,$72,'-' BNZ $72,1F 2H INCL p,1 JMP 1F % repeat 3H CMP $73,$71,'0' % if c < '0' or c > '9' BN $73,4F % then print err and halt program CMP $73,$71,'9' BP $73,4F SUB $71,$71,'0' % 'extract' number MUL $70,$70,10 ADD $70,$70,$71 % N = 10 * N + digit INCL p,1 1H LDBU $71,p % get next digit PBNZ $71,3B % until end of string CMP $72,$72,0 BNZ $72,2F % if marked negative NEG $70,$70 % then make negative 2H GO $127,$127,0 % return (N)

4H LDA p,ILLH TRAP 0,Fputs,StdErr LDA p,pp TRAP 0,Fputs,StdErr LDA p,ILLT TRAP 0,Fputs,StdErr TRAP 0,Halt,0

// entrance of program // e.g. ~> mmix compare2ints A B // Main CMP p,argc,3 % main (argc, argv) { BZ p,1F % if argc == 3 then continue LDA p,ERR % else print wrong number of args TRAP 0,Fputs,StdErr TRAP 0,Halt,0 // get ints A and B 1H LDOU p,argv,8 % fetch addres of first int GO $127,readInt % read int A ADD A,$70,0

LDOU p,argv,16 GO $127,readInt % read int B ADD B,$70,0

// perform comparison CMP A,A,B % case compare A B LDA p,LT BN A,2F % LT: print 'LT' LDA p,EQ BZ A,2F % EQ: print 'EQ' LDA p,GT % _ : print 'GT' 2H TRAP 0,Fputs,StdOut % print result TRAP 0,Halt,0</lang> Example of use: 

~/MIX/MMIX/Progs> mmix compare2ints 121 122
A is less than B

~/MIX/MMIX/Progs> mmix compare2ints 121 121
A equals B

~/MIX/MMIX/Progs> mmix compare2ints 121 120
A is greater than B

~/MIX/MMIX/Progs> mmix compare2ints -121 -122
A is greater than B

~/MIX/MMIX/Progs> mmix compare2ints -121 -121
A equals B

~/MIX/MMIX/Progs> mmix compare2ints -121 -120
A is less than B

Modula-3

<lang modula3>MODULE Main;

FROM IO IMPORT Put, GetInt; FROM Fmt IMPORT Int;

VAR a,b: INTEGER;

BEGIN 

 a := GetInt();
 b := GetInt();
 IF a < b THEN
   Put(Int(a) & " is less than " & Int(b) & "\n");
 ELSIF a = b THEN
   Put(Int(a) & " is equal to " & Int(b) & "\n");
 ELSIF a > b THEN
   Put(Int(a) & " is greater than " & Int(b) & "\n");
 END;

END Main.</lang>

Oberon-2

<lang oberon2>MODULE Compare; 

  IMPORT In, Out;

  VAR a,b: INTEGER;

BEGIN 

  In.Int(a);
  In.Int(b);
  IF a < b THEN
     Out.Int(a,0);
     Out.String(" is less than ");
     Out.Int(b,0);
     Out.Ln;
  ELSIF a = b THEN
     Out.Int(a,0);
     Out.String(" is equal to ");
     Out.Int(b,0);
     Out.Ln;
  ELSIF a > b THEN
     Out.Int(a,0);
     Out.String(" is greater than ");
     Out.Int(b,0);
     Out.Ln;
  END;

END Compare.</lang>

OCaml

<lang ocaml>let my_compare a b = 

 if      a < b then "A is less than B"
 else if a > b then "A is greater than B"
 else if a = b then "A equals B"
 else "cannot compare NANs"

let () = 

 let a = read_int ()
 and b = read_int () in
 print_endline (my_compare a b)</lang>

Octave

<lang octave>printf("Enter a: "); a = scanf("%d", "C"); printf("Enter b: "); b = scanf("%d", "C"); if (a > b) 

 disp("a greater than b");

elseif (a == b) 

 disp("a equal to b");

elseif (a < b) 

 disp("a less than b");

endif</lang>

Oz

<lang oz>functor import 

 Application(exit) 
 Open(text file)

define

Txt = class from Open.file Open.text end Stdout = {New Open.file init(name:stdout)} Stdin = {New Txt init(name:stdin)}

proc{Print Msg} 

 {Stdout write(vs:Msg)}

end

fun{GetInt Prompt} 

 {Print Prompt}
 {StringToInt {Stdin getS($)}}

end

Int1 = {GetInt "Enter 1st Integer:"} Int2 = {GetInt "Enter 2nd Integer:"}

if(Int1 < Int2) then {Print Int1#" less than "#Int2} end if(Int1 > Int2) then {Print Int1#" greater than "#Int2} end if(Int1 == Int2) then {Print Int1#" equal to "#Int2} end

{Application.exit 0} end</lang>

Pascal

<lang pascal>program compare(input, output)

var 

a, b: integer;

begin 

if (a < b) then writeln(a, ' is less than ', b);
if (a = b) then writeln(a, ' is equal to ', b);
if (a > b) then writeln(a, ' is greater than ', b);

end.</lang>

Perl

Works with: Perl version 5.x

Separate tests for less than, greater than, and equals

<lang perl>sub test_num { 

   my $f = shift;
   my $s = shift;
   if ($f < $s){
       return -1; # returns -1 if $f is less than $s
   } elsif ($f > $s) {
       return 1; # returns 1 if $f is greater than $s
   } elsif ($f == $s) {
  1. = operator is an assignment
  2. == operator is a numeric comparison
      return 0; # returns 0 $f is equal to $s
   };

};</lang>

All three tests in one. If $f is less than $s return -1, greater than return 1, equal to return 0

<lang perl>sub test_num { 

   return $_[0] <=> $_[1];

};</lang> Note: In Perl, $a and $b are (kind of) reserved identifiers for the built-in sort function. It's good style to use more meaningful names, anyway.

Perl 6

Works with: Rakudo version #22 "Thousand Oaks"

<lang perl6>my Int $a = floor $*IN.get; my Int $b = floor $*IN.get;

if $a < $b { 

   say 'Less';

} elsif $a > $b { 

   say 'Greater';

} elsif $a == $b { 

   say 'Equal';

}</lang>

With cmp:

<lang perl6>say <Less Equal Greater>[($a cmp $b) + 1];</lang>

PHP

<lang php><?php

echo "Enter an integer [int1]: "; fscanf(STDIN, "%d\n", $int1); if(!is_numeric($int1)) { 

 echo "Invalid input; terminating.\n";
 exit(1);      // return w/ general error

}

echo "Enter an integer [int2]: "; fscanf(STDIN, "%d\n", $int2); if(!is_numeric($int2)) { 

 echo "Invalid input; terminating.\n";
 exit(1);      // return w/ general error

}

// now $int1 and $int2 are numbers. // for simplicity, this does not explicitly examine types

if($int1 < $int2) 

 echo "int1 < int2\n";

if($int1 == $int2) 

 echo "int1 = int2\n";

if($int1 > $int2) 

 echo "int1 > int2\n";

?></lang> Note that this works from the command-line interface only, whereas PHP is usually executed as CGI.

Pop11

<lang pop11>;;; Comparison procedure define compare_integers(x, y); if x > y then 

  printf('x is greater than y\n');

elseif x < y then 

  printf('x is less than y\n');

elseif x = y then 

  printf('x equals y\n');

endif; enddefine;

Setup token reader

vars itemrep; incharitem(charin) -> itemrep;

Read numbers and call comparison procedure

compare_integers(itemrep(), itemrep());</lang>

PowerShell

<lang powershell>$a = [int] (Read-Host a) $b = [int] (Read-Host b)

if ($a -lt $b) { 

   Write-Host $a is less than $b`.

} elseif ($a -eq $b) { 

   Write-Host $a is equal to $b`.

} elseif ($a -gt $b) { 

   Write-Host $a is greater than $b`.

}</lang>

Python

<lang Python>#!/usr/bin/env python a = int(raw_input('Enter value of a: ')) b = int(raw_input('Enter value of b: '))

if a < b: 

   print 'a is less than b'

elif a > b: 

   print 'a is greater than b'

elif a == b: 

   print 'a is equal to b'</lang>

(Note: in Python3 raw_input() will become input().).

An alternative implementation could use a Python dictionary to house a small dispatch table to be indexed by the results of the build-in cmp() function. cmp() returns a value suitable for use as a comparison function in a sorting algorithm: -1, 0 or 1 for <, = or > respectively. Thus we could use:

<lang Python>#!/usr/bin/env python import sys try: 

  a = int(raw_input('Enter value of a: '))
  b = int(raw_input('Enter value of b: '))

except (ValueError, EnvironmentError), err: 

  print sys.stderr, "Erroneous input:", err
  sys.exit(1)

dispatch = { 

   -1: 'is less than',
    0: 'is equal to',
    1: 'is greater than'
    }
print a, dispatch[cmp(a,b)], b</lang>

In this case the use of a dispatch table is silly. However, more generally in Python the use of dispatch dictionaries or tables is often preferable to long chains of elif' clauses in a condition statement. Python's support of classes and functions (including currying, partial function support, and lambda expressions) as first class objects obviates the need for a "case" or "switch" statement.

R

<lang R>print("insert number a") a <- scan(what=numeric(0), nmax=1) print("insert number b") b <- scan(what=numeric(0), nmax=1) if ( a < b ) { 

 print("a is less than b")

} else if ( a > b ) { 

 print("a is greater than b")

} else if ( a == b ) { # could be simply else of course... 

 print("a and b are the same")

}</lang>


REBOL

<lang REBOL> REBOL [ Title: "Comparing Two Integers" Author: oofoe Date: 2009-12-04 URL: http://rosettacode.org/wiki/Comparing_two_integers ]

a: ask "First integer? " b: ask "Second integer? "

relation: [ a < b "less than" a = b "equal to" a > b "greater than" ] print [a "is" case relation b] </lang>

Ruby

Gets is used to get input from the STDIN and 'to_i' is used to convert the string into an integer. This is not explicitly necessary, since strings will be compared correctly too. If two strings are entered they will be considered equal using this method. <lang ruby>a = gets( "enter a value for a: ").to_i b = gets( "enter a value for b: ").to_i

print "a is less than b" if a < b print "a is greater than b" if a > b print "a is equal to b" if a == b</lang>

Scheme

<lang scheme>(define (my-compare a b) 

 (cond ((< a b) "A is less than B")
       ((> a b) "A is greater than B")
       ((= a b) "A equals B")))

(my-compare (read) (read))</lang>

Slate

<lang slate>[ |:a :b | 

( a > b ) ifTrue: [ inform: 'a greater than b\n' ].
( a < b ) ifTrue: [ inform: 'a less than b\n' ].
( a = b ) ifTrue: [ inform: 'a is equal to b\n' ].

] applyTo: {Integer readFrom: (query: 'Enter a: '). Integer readFrom: (query: 'Enter b: ')}.</lang>

Smalltalk

<lang smalltalk>| a b | 'a = ' display. a := (stdin nextLine asInteger). 'b = ' display. b := (stdin nextLine asInteger). ( a > b ) ifTrue: [ 'a greater than b' displayNl ]. ( a < b ) ifTrue: [ 'a less than b' displayNl ]. ( a = b ) ifTrue: [ 'a is equal to b' displayNl ].</lang>

SNUSP

There are no built-in comparison operators, but you can (destructively) check which of two adjacent cells is most positive. <lang snusp>++++>++++ a b !/?\<?\# a=b 

              > -  \#  a>b
              - <
         a<b #\?/</lang>

Standard ML

<lang sml>fun compare_integers(a, b) = 

 if a < b then print "A is less than B\n"
 if a > b then print "A is greater than B\n"
 if a = b then print "A equals B\n"

fun test () =
 let
   open TextIO
   val SOME a = Int.fromString (input stdIn)
   val SOME b = Int.fromString (input stdIn)
 in
   compare_integers (a, b)
 end
   handle Bind => print "Invalid number entered!\n"</lang>

Tcl

This is not how one would write this in Tcl, but for the sake of clarity:

<lang tcl>puts "Please enter two numbers:"

gets stdin x gets stdin y

if { $x > $y } { puts "$x is greater than $y" } if { $x < $y } { puts "$x is less than $y" } if { $x == $y } { puts "$x equals $y" }</lang>

Other comparison operators are "<=", ">=" and "!=".

Note that Tcl doesn't really have a notion of a variable "type" - all variables are just strings of bytes and notions like "integer" only ever enter at interpretation time. Thus the above code will work correctly for "5" and "6", but "5" and "5.5" will also be compared correctly. It will not be an error to enter "hello" for one of the numbers ("hello" is greater than any integer). If this is a problem, the type can be expressly cast

<lang tcl>if {int($x) > int($y)} { puts "$x is greater than $y" }</lang>

or otherwise type can be checked with "if { string is integer $x }..."

Note that there is no substitution/evaluation here anywhere: entering "3*5" and "15" will parse "3*5" as a non-numerical string (like "hello") and thus the result will be "3*5 is greater than 15".

A variant that iterates over comparison operators, demonstrated in an interactive tclsh: <lang Tcl>% set i 5;set j 6 % foreach {o s} {< "less than" > "greater than" == equal} {if [list $i $o $j] {puts "$i is $s $j"}} 5 is less than 6 % set j 5 % foreach {o s} {< "less than" > "greater than" == equal} {if [list $i $o $j] {puts "$i is $s $j"}} 5 is equal 5 % set j 4 % foreach {o s} {< "less than" > "greater than" == equal} {if [list $i $o $j] {puts "$i is $s $j"}} 5 is greater than 4</lang>

TI-89 BASIC

<lang ti89b>Local a, b, result Prompt a, b If a < b Then 

 "<" → result

ElseIf a = b Then 

 "=" → result

ElseIf a > b Then 

 ">" → result

Else 

 "???" → result

EndIf Disp string(a) & " " & result & " " & string(b)</lang>

Toka

<lang toka>[ ( a b -- ) 

 2dup < [ ." a is less than b\n" ] ifTrue
 2dup > [ ." a is greater than b\n" ] ifTrue
      = [ ." a is equal to b\n" ] ifTrue

] is compare-integers

1 1 compare-integers 2 1 compare-integers 1 2 compare-integers</lang>

V

<lang v>[compare 

 [ [>] ['less than' puts]
   [<] ['greater than' puts]
   [=] ['is equal' puts]
 ] when].

|2 3 compare 

greater than

|3 2 compare 

less than

|2 2 compare 

is equal</lang>

Visual Basic .NET

Platform: .NET

Works with: Visual Basic .NET version 9.0+

<lang vbnet>Sub Main() 

   Dim a = CInt(Console.ReadLine)
   Dim b = CInt(Console.ReadLine)

   'Using if statements
   If a < b Then Console.WriteLine("a is less than b")
   If a = b Then Console.WriteLine("a equals b")
   If a > b Then Console.WriteLine("a is greater than b")

   'Using Case
   Select Case a
       Case Is < b
           Console.WriteLine("a is less than b")
       Case b
           Console.WriteLine("a equals b")
       Case Is > b
           Console.WriteLine("a is greater than b")
   End Select

End Sub</lang>

XSLT

Because XSLT uses XML syntax, the less than and greater than operators which would normally be written '<' and '>' must be escaped using character entities, even inside of XPath expressions.

<lang xml><xsl:template name="compare"> 

 <xsl:param name="a" select="1"/>
 <xsl:param name="b" select="2"/>
 <fo:block>
 <xsl:choose>
   <xsl:when test="$a < $b">a < b</xsl:when>
   <xsl:when test="$a > $b">a > b</xsl:when>
   <xsl:when test="$a = $b">a = b</xsl:when>
 </xsl:choose>
 </fo:block></lang>
</xsl:template>
Retrieved from "https://rosettacode.org/wiki/Integer_comparison?oldid=28284"