show me that double

double.js

'use strict';

const number = 100;
// see the actual bits, since JS uses 64-bit doubles
let buffer = new ArrayBuffer(8);
let doubleLoader = new Float64Array(buffer);
doubleLoader[0] = number;
let bytes = new Uint8Array(buffer);
// output the bytes
console.log([].slice.call(bytes));

// give me pad left or give me death

const padLeft = (s, char, len) => s.length >= len ? s : Array(len - s.length + 1).join(char) + s;


// output the bits
console.log([].map.call(bytes, (v) => padLeft(v.toString(2), '0', 8)).join(''));