[Edit]

JavaScript - check if number is even (Vanilla JS)

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Created by:

Palus-Bear

1016

In this short article, we would like to show how check if number is even using JavaScript.

Quick solution:

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if (number % 2 === 0) {
    // ...
}

Even numbers:

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... -8  -6  -4  -2   0   2   4   6   8 ...

Practical example

Edit

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function isEven(number) {
    return number % 2 === 0;
}
​
​
// Usage example:
​
console.log( isEven(0) );   // true      // even
console.log( isEven(1) );   // false
console.log( isEven(2) );   // true      // even
console.log( isEven(3) );   // false
console.log( isEven(4) );   // true      // even
console.log( isEven(5) );   // false
​
console.log( isEven(-1) );  // false
console.log( isEven(-2) );  // true      // even
console.log( isEven(-3) );  // false
console.log( isEven(-4) );  // true      // even
console.log( isEven(-5) );  // false

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Alternative solution

Edit

In this section, you can find solution that uses bitwise operator.

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function isEven(number) {
    return (number & 1) === 0;
}
​
​
// Usage example:
​
console.log( isEven(0) );   // true      // even
console.log( isEven(1) );   // false
console.log( isEven(2) );   // true      // even
console.log( isEven(3) );   // false
console.log( isEven(4) );   // true      // even
console.log( isEven(5) );   // false
​
console.log( isEven(-1) );  // false
console.log( isEven(-2) );  // true      // even
console.log( isEven(-3) );  // false
console.log( isEven(-4) );  // true      // even
console.log( isEven(-5) );  // false