How do you check a number is even or odd in php?

View Discussion

Improve Article

Save Article

View Discussion

Improve Article

Save Article

A number is called even if the number is divisible by 2 and is called odd if it is not divisible by 2. Given a number, we need to check whether it is odd or even in PHP.

Examples :

Input : 42
Output : Even
Explanation: The number 42 is divisible by 2

Input : 39
Output : Odd
Explanation: The number 39 is not divisible by 2

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

We can solve this problem in two different ways as described below:

1. Using modulo [%] operator: This is the simplest method of checking for even and odd and in this method, we simply check whether the number is divisible by 2 or not using the modulo ‘%’ operator.

   Below program explains the above approach:
   

   PHP

   
   Output :

   Odd
   

   Time Complexity: O[1]

2. Recursive method: In the recursive approach, we reduce the number by 2 in each recursive call. If the final number is 0 then its even or else it is 1, the result will be odd.
   Below is the implementation of above approach:
   

   PHP

   
   Output :

   Odd
   

   Time Complexity: O[n]

3. Using Bit Manipulation:
   In this method we will find bit-wise AND of the number with 1. If the bit-wise AND is 1, then the number is odd, else even.

   Below is the implementation of above idea.

   PHP

   
   Output :

   Odd
   

   Time Complexity: O[1]

PHP is a server-side scripting language designed specifically for web development. You can learn PHP from the ground up by following this PHP Tutorial and PHP Examples.