Even or odd function program in c

c program to check odd or even: We will determine whether a number is odd or even by using different methods all are provided with a code in c language. As you have study in mathematics that in decimal number system even numbers are divisible by 2 while odd are not so we may use modulus operator(%) which returns remainder, For example 4%3 gives 1 ( remainder when four is divided by three). Even numbers are of the form 2*p and odd are of the form (2*p+1) where p is is an integer.

C program to check odd or even using modulus operator
#include<stdio.h>

main()
{
   int n;

   printf("Enter an integer\n");
   scanf("%d",&n);

   if ( n%2 == 0 )
      printf("Even\n");
   else
      printf("Odd\n");

   return 0;
}
We can use bitwise AND (&) operator to check odd or even, as an example consider binary of 7 (0111) when we perform 7 & 1 the result will be one and you may observe that the least significant bit of every odd number is 1, so ( odd_number & 1 ) will be one always and also ( even_number & 1 ) is zero.

C program to check odd or even using bitwise operator
#include<stdio.h>

main()
{
   int n;

   printf("Enter an integer\n");
   scanf("%d",&n);

   if ( n & 1 == 1 )
      printf("Odd\n");
   else
      printf("Even\n");

   return 0;
}
Find odd or even using conditional operator
#include<stdio.h>

main()
{
   int n;

   printf("Input an integer\n");
   scanf("%d",&n);

   n%2 == 0 ? printf("Even\n") : printf("Odd\n");

   return 0;
}
C program to check odd or even without using bitwise or modulus operator
#include<stdio.h>

main()
{
   int n;

   printf("Enter an integer\n");
   scanf("%d",&n);

   if ( (n/2)*2 == n )
      printf("Even\n");
   else
      printf("Odd\n");

   return 0;
}
In c programming language when we divide two integers we get an integer result, For example the result of 7/3 will be 2.So we can take advantage of this and may use it to find whether the number is odd or even. Consider an integer n we can first divide by 2 and then multiply it by 2 if the result is the original number then the number is even otherwise the number is odd. For example 11/2 = 5, 5*2 = 10 ( which is not equal to eleven), now consider 12/2 = 6 and 6 *2 = 12 ( same as original number). These are some logic which may help you in finding if a number is odd or not.