JavaScript - check if number is power of 2

In this short article, we would like to show how to check if number is power of 2 using JavaScript.

Quick solution:

// ONLINE-RUNNER:browser;

const isPower = (value) => value > 0 && (value & (value - 1)) === 0;


// Usage example:

console.log(isPower(0));     // false

console.log(isPower(1));     // true
console.log(isPower(2));     // true
console.log(isPower(4));     // true
console.log(isPower(8));     // true
console.log(isPower(16));    // true
console.log(isPower(32));    // true
console.log(isPower(64));    // true
console.log(isPower(128));   // true
console.log(isPower(256));   // true
console.log(isPower(512));   // true
console.log(isPower(1024));  // true

console.log(isPower(10));    // false
console.log(isPower(20));    // false
console.log(isPower(30));    // false
console.log(isPower(40));    // false
console.log(isPower(50));    // false