js

Books on JavaScript:

• Stoyan Stefanov - JavaScript Patterns
• Douglas Crockford - JavaScript The Good Parts

Douglas Crockford - "JavaScript The Good Parts" on GoogleTechTalks

• jslint.com - The JavaScript Code Quality Tool

Creating an Object in js

var person = {
  firstName : "John",
  lastName : "Doe",
  sayHi : function() {
   return "Hi there"; 
  }
};
console.log( person.firstName + person.lastName + person.sayHi ); // returns 'John Doe Hi there'

/*var person = new Object();
person.firstName = "John";
person.lastName = "Doe";
person.sayHi = function() {
  return "Hi there";
};*/

Factory functions in js

var createPerson = function(firstName, lastName) {
  return {
    firstName : firstName,
    lastName : lastName,
    sayHi : function() {
      return "Hi there";
    }
  };
};

var johnDoe = createPerson("John", "Doe");
console.log( johnDoe.firstName ); // returns 'John'

var janeDoe = createPerson("Jane", "Doe");
console.log( janeDoe.firstName ); // returns 'Jane'

Create array of objects in js

var arr = [];
var img_list = $('.related-lots li');
$.each(img_list, function(index, item){
var obj = {
		image_url: image_url_str,
		href: href_url
	};
	arr.push(obj);
});

var person = {
	getName: function () { // public method
		return this._getFirst() + ' ' + this._getLast();
	},
	_getFirst: function () { // private method
		// code
	},
	_getLast: function () { // private method
		// code
	}
};

var myApplication = function(){
  var name = 'Chris';
  var age = '34';
  var status = 'single';
  function createMember(){
    // [...]
  }
  function getMemberDetails(){
    // [...]
  }
  return{
    create:createMember,
    get:getMemberDetails
  }
}();
//myApplication.get() and myApplication.create() now work.

JavaScript callback pattern

function func1(callback) {
	// some code
	callback();
	// some code
}
function func2() {
	// some code
}
func1(func2);

JavaScript callback example

// refactored findNodes() to accept a callback
var findNodes = function (callback) {
	var i = 100000, // big, heavy loop
		nodes = [], // stores the result
		found; // the next node found
	// check if callback is callable
	if (typeof callback !== "function") {
		callback = false;
	}
	while (i) {
		i -= 1;
		// complex logic here...
		// now callback:
		if (callback) {
			callback(found);
		}
		nodes.push(found);
	}
	return nodes;
};

// a callback function
var hide = function (node) {
	node.style.display = "none";
};
// find the nodes and hide them as you go
findNodes(hide);

// or you can pass an anonymous callback
findNodes(function (node) {
	node.style.display = "block";
});




<h3>Borrow and bind methods</h3>


var one = {
    name: "object",
    say: function (greet) {
        return greet + ", " + this.name;
    }
};
one.say('hi'); // "hi, object"

var two = {
    name: "another object"
};
one.say.apply(two, ['hello']); // "hello, another object"

JavaScript percents (percentage): var p = Math.round(Math.random() * 100);

Interview question:

const a = {
	i: 1,
	toString: function() {
		return a.i++;
	}
}
if(a == 1 && a == 2 && a == 3) {
	console.log('hi');
}