gistfile1.js

// Assignment:
var number   = 42
var opposite = true

// Conditions:
number = opposite ? -42 : number

// Functions:
var square = function(x){ return x * x }

// Arrays:
var list = [1, 2, 3, 4, 5]

// Objects:
var math = {
  root: Math.sqrt,
  square: square,
  cube: function(x){ return x * square(x) }
};

// Splats:
// This is so rare nobody cares of a few lines of code.
var race = function() {
  var winner = arguments[0]
  var runners = arguments.length >= 2 ? [].slice.call(arguments, 1) : []
  return print(winner, runners)
};

// Existence: Oh hell, why not just define the variable so you can use it like a variable?
if(typeof elvis !== "undefined" && elvis !== null) alert("I knew it!")

// Array comprehensions (JS 1.6):
var cubes = list.map(function(x){ return math.cube(x) }