Check if a Number is Odd or Even using Bitwise Operators

Given a number N, the task is to check whether the number is even or odd using Bitwise Operators.

Examples:

Input: N = 11
Output: Odd
Input: N = 10
Output: Even

Following Bitwise Operators can be used to check if a number is odd or even:

1. Using Bitwise XOR operator:
The idea is to check whether the last bit of the number is set or not. If the last bit is set then the number is odd, otherwise even.
As we know bitwise XOR Operation of the Number by 1 increment the value of the number by 1 if the number is even otherwise it decrements the value of the number by 1 if the value is odd.

Below is the implementation of the above approach:

C++

// C++ program to check for even or odd
// using Bitwise XOR operator
 
#include <iostream>
using namespace std;
 
// Returns true if n is even, else odd
bool isEven(int n)
{
 
    // n^1 is n+1, then even, else odd
    if ((n ^ 1) == (n + 1))
        return true;
    else
        return false;
}
 
// Driver code
int main()
{
    int n = 100;
    isEven(n) ? cout << "Even" : cout << "Odd";
 
    return 0;
}

Java

// Java program to check for even or odd
// using Bitwise XOR operator
class GFG {
 
    // Returns true if n is even, else odd
    static boolean isEven(int n)
    {
 
        // n^1 is n+1, then even, else odd
        if ((n ^ 1) == (n + 1))
            return true;
        else
            return false;
    }
 
    // Driver code
    public static void main(String[] args)
    {
        int n = 100;
        System.out.print(isEven(n) == true ? "Even"
                                           : "Odd");
    }
}
 
// This code is contributed by Rajput-Ji

Python3

# Python3 program to check for even or odd
# using Bitwise XOR operator
 
# Returns true if n is even, else odd
 
 
def isEven(n):
 
    # n^1 is n+1, then even, else odd
    if ((n ^ 1) == (n + 1)):
        return True
    else:
        return False
 
 
# Driver code
if __name__ == "__main__":
    n = 100
    print("Even") if isEven(n) else print("Odd")
 
# This code is contributed by AnkitRai01

C#

// C# program to check for even or odd
// using Bitwise XOR operator
using System;
 
class GFG {
 
    // Returns true if n is even, else odd
    static bool isEven(int n)
    {
 
        // n^1 is n+1, then even, else odd
        if ((n ^ 1) == (n + 1))
            return true;
        else
            return false;
    }
 
    // Driver code
    public static void Main(String[] args)
    {
        int n = 100;
        Console.Write(isEven(n) == true ? "Even" : "Odd");
    }
}
 
// This code is contributed by Rajput-Ji

Javascript

<script>
 
// JavaScript program to check for even or odd
// using Bitwise XOR operator
 
// Returns true if n is even, else odd
function isEven(n)
{
 
    // n^1 is n+1, then even, else odd
    if ((n ^ 1) == (n + 1))
        return true;
    else
        return false;
}
 
// Driver code
 
    let n = 100;
    isEven(n)
? document.write("Even")
: document.write("Odd");
 
// This code is contributed by Surbhi Tyagi.
 
</script>

Output

Even

Time Complexity: O(1)
Auxiliary Space: O(1)

2. Using Bitwise AND operator:
The idea is to check whether the last bit of the number is set or not. If last bit is set then the number is odd, otherwise even.
As we know bitwise AND Operation of the Number by 1 will be 1, If it is odd because the last bit will be already set. Otherwise, it will give 0 as output.

Below is the implementation of the above approach:

C++

// C++ program to check for even or odd
// using Bitwise AND operator
#include <iostream>
using namespace std;
 
// Returns true if n is even, else odd
bool isEven(int n)
{
    // n&1 is 1, then odd, else even
    return (!(n & 1));
}
 
// Driver code
int main()
{
    int n = 101;
    isEven(n) ? cout << "Even" : cout << "Odd";
    return 0;
}

Java

// Java program to check for even or odd
// using Bitwise AND operator
class GFG {
 
    // Returns true if n is even, else odd
    static boolean isEven(int n)
    {
        // n&1 is 1, then odd, else even
        return ((n & 1) != 1);
    }
 
    // Driver code
    public static void main(String[] args)
    {
        int n = 101;
        System.out.print(isEven(n) == true ? "Even"
                                           : "Odd");
    }
}
 
// This code is contributed by PrinciRaj1992

Python3

# Python3 program to check for even or odd
# using Bitwise AND operator
 
# Returns true if n is even, else odd
 
 
def isEven(n):
 
    # n&1 is 1, then odd, else even
    return (not(n & 1))
 
 
# Driver code
if __name__ == "__main__":
 
    n = 101
    if isEven(n):
        print("Even")
    else:
        print("Odd")
 
# This code is contributed by AnkitRai01

C#

// C# program to check for even or odd
// using Bitwise AND operator
using System;
 
class GFG {
 
    // Returns true if n is even, else odd
    static bool isEven(int n)
    {
        // n&1 is 1, then odd, else even
        return ((n & 1) != 1);
    }
 
    // Driver code
    public static void Main()
    {
        int n = 101;
        Console.Write(isEven(n) == true ? "Even" : "Odd");
    }
}
 
// This code is contributed by AnkitRai01

Javascript

<script>
// javascript program to check for even or odd
// using Bitwise AND operator
  
     
// Returns true if n is even, else odd
function isEven(n)
{
    // n&1 is 1, then odd, else even
    return ((n & 1)!=1);
}
     
// Driver code
var n = 101;
document.write(isEven(n) == true ? "Even" : "Odd");
 
// This code is contributed by Princi Singh
</script>

Output

Odd

Time Complexity: O(1)
Auxiliary Space: O(1)

3. Using Bitwise OR operator: The idea is to check whether the last bit of the number is set or not. If the last bit is set then the number is odd, otherwise even. As we know bitwise OR Operation of the Number by 1 increment the value of the number by 1 if the number is even otherwise it will remain unchanged. So, if after OR operation of number with 1 gives a result that is greater than the number then it is even and we will return true otherwise it is odd and we will return false.

Below is the implementation of the above approach:

C++

// C++ program to check for even or odd
// using Bitwise OR operator
 
#include <iostream>
using namespace std;
 
// Returns true if n is even, else odd
bool isEven(int n)
{
 
    // n|1 is greater than n, then even, else odd
    if ((n | 1) > n)
        return true;
    else
        return false;
}
 
// Driver code
int main()
{
    int n = 100;
    isEven(n) ? cout << "Even" : cout << "Odd";
 
    return 0;
}

Java

// Java program to check for even or odd
// using Bitwise OR operator
class GFG {
    // Returns true if n is even, else odd
    static boolean isEven(int n)
    {
 
        // n|1 is greater than n, then even, else odd
        if ((n | 1) > n)
            return true;
        else
            return false;
    }
 
    // Driver code
    public static void main(String[] args)
    {
        int n = 100;
        System.out.print(isEven(n) == true ? "Even"
                                           : "Odd");
    }
}

Python3

# Python3 program to check for even or odd
# using Bitwise OR operator
 
# Returns true if n is even, else odd
 
 
def isEven(n):
 
    # n|1 is greater than n, then even, else odd
    if (n | 1 > n):
        return True
    else:
        return False
 
 
# Driver code
if __name__ == "__main__":
    n = 100
    print("Even") if isEven(n) else print("Odd")

C#

// C# program to check for even or odd
// using Bitwise XOR operator
using System;
 
class GFG {
 
    // Returns true if n is even, else odd
    static bool isEven(int n)
    {
 
        // n|1 is greater than n, then even, else odd
        if ((n | 1) > n)
            return true;
        else
            return false;
    }
 
    // Driver code
    public static void Main(String[] args)
    {
        int n = 100;
        Console.Write(isEven(n) == true ? "Even" : "Odd");
    }
}
 
// This code is contributed by Rajput-Ji

Javascript

<script>
// javascript program to check for even or odd
// using Bitwise OR operator
 
// Returns true if n is even, else odd
function isEven(n)
{
 
    // n|1 is greater than n, then even, else odd
    if ((n | 1) > n)
        return true;
    else
        return false;
}
 
// Driver code
var n = 100;
document.write(isEven(n) == true ? "Even" : "Odd");
 
// This code is contributed by Amit Katiyar.
</script>

Output

Even

Time Complexity: O(1)
Auxiliary Space: O(1)

4. Using bitwise left and right shift operators: The idea is to check whether a number remains the same after performing some operations i.e. bitwise left and right shift. When we do a bitwise right shift of the number then the last bit of the number is removed whenever it is 1 or 0. After that performing the left shift to the number by default a new binary is added to the last bit which is 0, by displacement of one bit by one. Even numbers remain the same but odd changed its value. compare the initial and final values of the number to check number is even or odd.

Below is the implementation of the above approach.

C++

#include <iostream>
using namespace std;
 
int main()
{
  int num = 2;
  // To take input from user, prefer below code
  // int num;
  // cout << "Enter a number: \n";
  // cin >> num;
  if (num == (num >> 1) << 1) {
    cout << num << " is even." << endl;
  }
  else {
    cout << num << " is not even." << endl;
  }
  // Below is short hand
  // num == (num >> 1) << 1 ? cout << num << " is even."
  // << endl : cout << num << " is not even." << endl;
  return 0;
}
 
// This code is contributed by lokeshpotta20

C

#include <stdio.h>
 
int main() {
 
  int num = 2 ;
   // To take input from user, prefer below code
   // int num ;
   // printf("Enter a number: \n");
   // scanf("%d",&num);
   
    if(num == ( num>>1 ) << 1){
        printf("%d is even.\n",num);
     }
    else{
         printf("%d is not even.\n",num);
     }
 
   // below is short hand
   // num==(num>>1)<<1? printf("%d is even.\n",num):printf("%d is odd.\n",num);
   
    return 0;
}

Java

// Java program to check for even or odd
// using Bitwise OR operator
import java.util.*;
class GFG
{
   
  // Driver code
  public static void main(String[] args)
  {
    int num = 2 ;
     
    // To take input from user, prefer below code
    // int num ;
    // System.out.println("Enter a number: \n");
    // num = in.nextInt();
    if(num == ( num>>1 ) << 1){
      System.out.println(num + " is even.\n");
    }
    else{
      System.out.println(num + " is not even.\n");
    }
 
    // below is short hand
    // num==(num>>1)<<1?  System.out.println(num + " is even.\n"):System.out.println(num + "%d is not even.\n");
 
  }
}
 
// This code is contributed by abhijeet19430.

Python3

# Python3 program to check for even or odd
# using Bitwise OR operator
 
num = 2 ;
# To take input from user, prefer below code
# int num ;
# printf("Enter a number: \n");
# scanf("%d",&num);
 
if(num == ( num>>1 ) << 1):
    print(num, "is even.\n");
else:
     print(num, "is not even.\n");
 
 
# below is short hand
# num==(num>>1)<<1? printf("%d is even.\n",num):printf("%d is odd.\n",num);

C#

using System;
using System.Collections.Generic;
 
class GFG {
 
  public static void Main()
  {
    int num = 2 ;
 
    // To take input from user, prefer below code
    // int num ;
    // printf("Enter a number: \n");
    // scanf("%d",&num);
 
    if(num == ( num>>1 ) << 1){
      Console.Write(num+" is even.\n");
    }
    else{
      Console.Write(num+" is not even.\n");
    }
 
    // below is short hand
    // num==(num>>1)<<1? printf("%d is even.\n",num):printf("%d is odd.\n",num);
  }
}
 
// This code is contributed by ratiagarwal.

Javascript

let num = 2 ;
 
// To take input from user, prefer below code
// int num ;
// printf("Enter a number: \n");
// scanf("%d",&num);
 
if(num == ( num>>1 ) << 1){
    console.log(num, "is even.\n");
 }
else{
     console.log(num, "is not even.\n");
 }
 
// below is short hand
// num==(num>>1)<<1? printf("%d is even.\n",num):printf("%d is odd.\n",num);
 
// This code is contributed by poojaagarwal2.