running Javascript from Swift using JavaScriptCore (try this in a playground)

javascript.swift

import JavaScriptCore

let context = JSContext()

context.evaluateScript("var num = 5 + 5")
context.evaluateScript("var names = ['Grace', 'Ada', 'Margaret']")
context.evaluateScript("var triple = function(value) { return value * 3 }")
context.evaluateScript("names.sort()")
let tripleNum: JSValue = context.evaluateScript("triple(num)")

let x = context.evaluateScript(
    "x = {a: 1, b: ['blah'], c: { cat: 1.0 }}")

x.valueForProperty("a")
x.valueForProperty("b")
let o: JSValue = x.valueForProperty("c")

Forked from http://nshipster.com/javascriptcore/