mirror of
https://github.com/TheAlgorithms/JavaScript.git
synced 2025-07-04 07:29:47 +08:00
49 lines
1.4 KiB
JavaScript
49 lines
1.4 KiB
JavaScript
/*
|
|
* Even Number: https://simple.wikipedia.org/wiki/Even_number
|
|
*
|
|
* function to check if number is even
|
|
* return true if number is even
|
|
* else false
|
|
*/
|
|
|
|
/**
|
|
* @function isEven
|
|
* @description - Checking if number is even using divisibility by 2
|
|
*
|
|
* If number is divisible by 2 i.e remainder = 0, then it is even
|
|
* therefore, the function will return true
|
|
*
|
|
* If number is not divisible by 2 i.e remainder != 0, then it is not even i.e odd
|
|
* therefore, the function will return false
|
|
* @param {number} number
|
|
* @return {boolean}
|
|
*/
|
|
export const isEven = (number) => number % 2 === 0
|
|
|
|
/**
|
|
* @function isEvenBitwise
|
|
* @description - Checking if number is even using bitwise operator
|
|
* Bitwise AND (&) compares the bits of the 32
|
|
* bit binary representations of the number and
|
|
* returns a number after comparing each bit:
|
|
*
|
|
* 0 & 0 -> 0
|
|
* 0 & 1 -> 0
|
|
* 1 & 0 -> 0
|
|
* 1 & 1 -> 1
|
|
*
|
|
* For odd numbers, the last binary bit will be 1
|
|
* and for even numbers, the last binary bit will
|
|
* be 0.
|
|
*
|
|
* As the number is compared with one, all the
|
|
* other bits except the last will become 0. The
|
|
* last bit will be 0 for even numbers and 1 for
|
|
* odd numbers, which is checked with the use
|
|
* of the equality operator.
|
|
* @param {number} number
|
|
* @returns {boolean}
|
|
* @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_AND
|
|
*/
|
|
export const isEvenBitwise = (number) => (number & 1) === 0
|