Type conversion with Boolean, Number and String

conversion_boolean_number_string.js

Boolean(""); // false
Boolean(0); // false
Boolean(1); // true

Number("10");    // 10
Number("foo");   // NaN

String(10); // "10"

var stuff = ["", 1, undefined, { foo: "bar" }];

// Get only the truthy values inside stuff
var onlyValid = stuff.filter(Boolean); // [ 1, { foo: "bar" } ]

// Get only the numbers values inside stuff (Note: 0 is a falsy value so this won't work if 0 is in stuff)
var onlyNumbers = stuff.filter(Number); // [ 1 ]