JavaScript - check if number is odd (Vanilla JS)

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

Quick solution:

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

Odd numbers:

... -7  -5  -3  -1   1   3   5   7 ...

Practical example

// ONLINE-RUNNER:browser;

function isOdd(number) {
	return number % 2 !== 0;
}


// Usage example:

console.log( isOdd(0) );   // false
console.log( isOdd(1) );   // true      // odd
console.log( isOdd(2) );   // false
console.log( isOdd(3) );   // true      // odd
console.log( isOdd(4) );   // false
console.log( isOdd(5) );   // true      // odd

console.log( isOdd(-1) );  // true      // odd
console.log( isOdd(-2) );  // false
console.log( isOdd(-3) );  // true      // odd
console.log( isOdd(-4) );  // false
console.log( isOdd(-5) );  // true      // odd

Alternative solution

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

// ONLINE-RUNNER:browser;

function isOdd(number) {
	return (number & 1) !== 0;
}


// Usage example:

console.log( isOdd(0) );   // false
console.log( isOdd(1) );   // true      // odd
console.log( isOdd(2) );   // false
console.log( isOdd(3) );   // true      // odd
console.log( isOdd(4) );   // false
console.log( isOdd(5) );   // true      // odd

console.log( isOdd(-1) );  // true      // odd
console.log( isOdd(-2) );  // false
console.log( isOdd(-3) );  // true      // odd
console.log( isOdd(-4) );  // false
console.log( isOdd(-5) );  // true      // odd

See also

1. JavaScript - check if number is even (Vanilla JS)