JavaScript Basics

JavaScript at Mint and Beyond

var we = “so so so excited”; Variables

we = “so so so excited”; Global Variable

function sit(seat){ sitting = ‘sitting in the ’+seat+‘ seat’; alert(sitting);
} sit(‘front’); alert(sitting); sitting was set globally

function parting(chant){ var location = ‘Back Seat’, mood = ‘happy’,
over; } multiple variable declaration

(we == “so so so excited”) // true

(we === “so so so excited”) // more true

for(var i=0; i < 10; i++){ // ... }

while ( true ) { // for ever and ever
}

for(var node in object){ // ... }

Everything is an Object

function Car(seats){ // code } Car.prototype.mood = function(){ return ‘exciting’;
} var partyVenue = new Car();

var weekDays = [ ‘monday’, ‘tuesday’ ... ]; var weekDays
= new Array(‘monday’, ‘tuesday’ ... ); creating arrays

var seat = { position: ‘front’, activity: ‘kicking’ }; var
seat = new Object(); seat.position = ‘front’; seat.activity = ‘kicking’; creating objects

var App = { inlineSearch: function(){ ... }, ajaxPannels: function(){
... } }; namespacing

for(var node in object){ // ... }

typeof friday === “undefined” // true BB.isDef(friday) existence

if( thursday ){ // } undefined variables cause exceptions

var friday = {}; if( friday.now ) { // }
undefined attributes don’t

function friday(){ return ‘party’; } method

function (){ return ‘party’; } anonymous

(function (){ return ‘party’; }()); self executing anonymous

(function($){ // code that uses jQuery $ here }(jQuery)); pass
through variables into anonymous functions

elm.addEventListener(‘click’, function(e){ // event code }, false); native events

jQuery

$(‘div.car p.front-seat’); css selectors

$(‘div.car p[rel=“empty”]’); advanced selectors

var $car = $(‘div.car’), $frontSeat = $(‘p.front-seat’, $car); or $frontSeat
= $car.children(‘p.front-seat’); scoped selectors

$(function(){ // execute on DOMReady }); DOMReady Loader

$.each( ... ); object with methods

$(‘<div id=“friday”>partying</ div>’); create nodes

var $seats = $(‘div.seat’); use a $variable name for jQuery
objects

$(‘div.seat’); // [ node1, node2, node3 ... ] jQuery object
is an array of matched nodes

$(‘div.seat’).css(‘background’); get css value

$(‘div.seat’) .css(‘background’, ‘#bada55’); set value

$(‘div.seat’) .css(‘color’, ‘#bada55’) .addClass(‘party’) modifiers return a jQuery object

$friday.bind(‘click’, function(e){ e.preventDefault(); // parting }); jQuery events

BB.bodyID(‘users-index’, function(){ ... }); BB.bodyClass(‘users’, function(){ ... }); restricting execution

<body id=“search-index”> <form method=“get” action=“” id=“search”> <input type=“text” name=“q”> <button
type=“submit”>Search!</button> </form> <div id=“results”> </div> </body> a search page

BB.bodyID(‘search-index’, function(){ var $form = $(‘form#search’); BB.submitInline($form, { success: function(){
// success code here } } });

{ results: [ { title: ‘fun’, url: ‘/fun’ }, {
title: ‘excited’, url: ‘/excited’ }, ... ] } json response

<body id=“search-index”> <form method=“get” action=“” id=“search”> <input type=“text” name=“q”> <button
type=“submit”>Search!</button> </form> <div id=“results”> </div> </body> recap search page

BB.bodyID(‘search-index’, function(){ var $form = $(‘form#search’), $results = $(‘div#results’); BB.submitInline($form,
{ success: function(json){ $.each(json.results, function(i, data){ $results.append(‘<a href=“’+data.url +‘”>’+data.title+‘</a>’); }); } } });

Browser Development

function whichSeatShouldITake(){ var seats = [ ‘Front Left’, ‘Front Right’,
‘Back Left’, ‘Back Right’, ‘Back Middle’], random = Math.round(Math.random()*seats.length)); return “Just sit in the ” + seats[random] + “ seat and shut up”; }

JavaScript Basics

JavaScript Basics

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