Random bits of knowledge

boolean, number, string, null, undefined

console.log(typeof "JavaScript"); // "string"
console.log(typeof 10);           // "number"
console.log(typeof 5.1);          // "number"
console.log(typeof true);         // "boolean"
console.log(typeof undefined);    // "undefined"
console.log(typeof null);         // "object"

Array, Date, Error, Function, Object, RegExp

var items = new Array();
var now = new Date();
var error = new Error("Something bad happened.");
var func = new function("console.log('Hi');");
var object = new Object();
var re1 = new RegExp("\\d+","g");
var re2 = /\d+/g;