Check if two numbers are equal without using comparison operators

Difficulty Level : Easy
Last Updated : 05 Apr, 2021

Following are not allowed to use
1) Comparison Operators
2) String functions
Examples:

Input : num1 = 1233, num2 - 1233
Output : Same

Input : num1 = 223, num2 = 233
Output : Not Same

Method 1: The idea is to use XOR operator. XOR of two numbers is 0 if the numbers are same, otherwise non-zero.

C++

#include <iostream>
using namespace std;
  
// Finds if a and b are same.
void areSame(int a, int b)
{
   if (a^b)
       cout << "Not Same";
   else
       cout << "Same";
}
  
int main()
{ 
   areSame(10, 20);
}

Java

class GFG
{
    // Finds if a and b are same
    static void areSame(int a,int b)
    {
        if( (a ^ b) != 0 )
            System.out.println("Not Same");
        else
            System.out.println("Same");
    }
 
    public static void main(String args[])
    {
        areSame(10,20);
    }
     
}
// This code is contributed by Sumit Ghosh

Python

# Finds if a and b are same.
def areSame(a, b):
   if (a ^ b):
       print "Not Same"
   else:
       print "Same"
   
# Driver code
areSame(10, 20)
 
# This code is submitted by Sachin Bisht

C#

// C# program to check if 2
// numbers are same
using System;
 
class GFG
{
    // Finds if a and b are same
    static void areSame(int a, int b)
    {
        if( (a ^ b) != 0 )
          Console.Write("Not Same");
        else
          Console.Write("Same");
    }
    
    // Driver code
    public static void Main()
    {
                
        // Calling Function
        areSame(10, 20);
    }
     
}
 
// This code is contributed by Nitin Mittal.

PHP

<?php
 
// Finds if a and b are same.
function areSame($a, $b)
{
    if ($a ^ $b)
        echo "Not Same";
    else
        echo "Same";
}
 
// Driver Code
areSame(10, 20);
 
// This code is contributed by nitin mittal
?>

Javascript

<script>
 
// Finds if a and b are same.
 
function areSame(a, b)
{
if (a^b)
    document.write("Not Same");
else
    document.write("Same");
}
 
// Driver code
areSame(10, 20);
 
// This code is contributed by Surbhi Tyagi.
 
</script>

Output:

Not Same

Method 2: We can subtract the numbers. Same numbers yield 0. If answer is not 0, numbers are not same.

C++

// CPP code to check if 2 numbers are same
#include <bits/stdc++.h>
using namespace std;
 
// Finds if a and b are same
void areSame(int a, int b)
{
    if (!(a - b))
        cout << "Same";
    else
        cout << "Not Same";
}
 
// Driver code
int main()
{   
     areSame(10, 20);   
    return 0;
}

Java

// Java code to check if 2 numbers are same
class GFG{
 
    // Finds if a and b are same
    static void areSame(int a, int b)
    {
        if ((a - b) == 0)
            System.out.println("Same");
        else
            System.out.println("Not Same");
    }
  
    // Driver code
    public static void main(String args[])
    {   
        areSame(10, 20);   
     
    }
}
//This code is contributed by Sumit Ghosh

Python

# Python code to check if 2 numbers are same
 
# Finds if a and b are same
def areSame(a, b):
    if (not(a - b)):
        print "Same"
    else:
        print "Not Same"
# Driver code
areSame(10, 20)
 
# This code is submitted by Sachin Bisht

C#

// C# code to check if 2
// numbers are same
using System;
 
class GFG
{
 
    // Finds if a and b are same
    static void areSame(int a, int b)
    {
        if ((a - b) == 0)
            Console.Write("Same");
        else
            Console.Write("Not Same");
    }
 
    // Driver code
    public static void Main()
    {
         
        // Calling Function
        areSame(10, 20);
    }
}
 
// This code is contributed by Nitin Mittal.

PHP

<?php
// PHP code to check if 2
// numbers are same
 
// Finds if a and b are same
function areSame($a, $b)
{
    if (!($a - $b))
        echo "Same";
    else
        echo "Not Same";
}
 
// Driver code
areSame(10, 20);
 
// This code is contributed by nitin mittal
?>

Javascript

<script>
// javascript code to check if 2 numbers are same
  
 
// Finds if a and b are same
function areSame(a , b)
{
    if ((a - b) == 0)
        document.write("Same");
    else
        document.write("Not Same");
    }
  
    // Driver code
areSame(10, 20);
 
// This code contributed by Princi Singh
</script>

Output:

Not Same

This article is contributed by Rohit Thapliyal. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
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