console.log(Math.log2(3));
// expected output: 1.584962500721156

console.log(Math.log2(2));
// expected output: 1

console.log(Math.log2(1));
// expected output: 0

console.log(Math.log2(0));
// expected output: -Infinity

Math.log2(3);    // 1.584962500721156
Math.log2(2);    // 1
Math.log2(1);    // 0
Math.log2(0);    // -Infinity
Math.log2(-2);   // NaN
Math.log2(1024); // 10