JavaScript Patterns [O’Reilly]

jspatterns.js

/*
Chapter 3: Literals and Constructors
*/

// Object Constructor Catch
var o = new Object();
console.log(o.constructor.name);
var o = new Object(1);
console.log(o.constructor.name);
var o = new Object("str");
console.log(o.constructor.name);
var o = new Object(true);
console.log(o.constructor.name);


// Custom Constructor Functions
var Person = function(name) {
  this.name = name;
  this.say = function() {
    return "I am " + this.name;
  };
};


// Patterns for Enforcing new
// Self-Invoking Constructor
function Waffle() {
  if (!(this instanceof Waffle)) {
    return new Waffle();
  }
  this.tastes = "yummy";
}

Waffle.prototype.wantAnother = true;

var first = new Waffle(),
  second = Waffle();
console.log(first.tastes, second.tastes);
console.log(first.wantAnother, second.wantAnother);


// Array Literal
// Check for Array-ness
if (!Array.isArray) {
  Array.isArray = function(arg) {
    return Object.prototype.toString.call(arg) === "[object Array]";
  };
}


// JSON
// Working with JSON
var jstr = '{ "mykey": "my value" }';
var data = JSON.parse(jstr);
console.log(data.mykey);

var dog = {
  name: "Fido",
  dob: new Date(),
  legs: [1,2,3,4]
};
var jsonstr = JSON.stringify(dog);
console.log(jsonstr);



// http://www.slideshare.net/stoyan/javascript-patterns

function mixInThese() {
  var arg, prop, child = {};
  for(arg = 0; arg<arguments.length; arg++) {
    for(prop in arguments[arg]) {
      child[prop] = arguments[arg][prop];
    }
  }
  return child;
}

function extend(parent, child) {
  var i, child = child || {};
  for(i in parent) {
    child[i] = parent[i];
  }
  return child;
}