power of 4

by sramnan

JavaScript

function isPowerOfFour(num) {
        var mask = 0x55555555;
        return (( mask & num )!= 0 ) && isPowerofTwo(num);
    }
    function isPowerofTwo(n){
        return (n>0) && ( n == 1 || ( (n & (n-1)) ==0 ));
    }

console.log(isPowerOfFour(64));
console.log(parseInt(0xA));