Given an integer n, return true if it is a power of two. Otherwise, return false. An integer n is a power of two, if there exists an integer x such that n == 2x.

isPowerOfTwo.js

/**
 * @param {number} n
 * @return {boolean}
 */
var isPowerOfTwo = function(n) {
    // Powers of two must be positive integers greater than zero
    if (n < 1) {
        return false;
    }

    // Use bitwise AND to check if n has only one bit set
    return (n & (n -1)) === 0;
};