JS Basics

Basics

 History
 Variable Type
 Statement Review
 Battle against Coding Horror

Basics

History
 JavaScript – What a Dummy name nothing to do with
Java ! except the name & year of birthdate 1995
 Prefer the reference to EMACScript 5
last revision in december 2009

 Suffering as Popup langage and unconsistence
Comparing The « Grail » POO (Java / C++)

 New Dynamic from AJAX ( Web 2.0)
has become in 2007

 Recently NodeJS 2010 (JS on Server-Side)

Basics
 Cloud (rich Client-Side apps)

Variable Type 1/2

Boolean, Number, String, Date, Array, Object, Function, null, undefi
ned
var variable;
 undefined ?
Mutiple variable declaration at top of inner function
var variable1,
variable2,
variable2;

 Use simple quote as double quote to improve Basics
consistent and readability

Variable Type 2/2
 Use JSON to improve consistence
var comment = {
title: ‘my title’,
date: new Date(),
body: ‘my comment’
};
 Declare Array with [] and Object with {}
var comments = [];
comments.push(comment);
comments.render = function() {
/* comments collection rendering */
}
Basics
Prefer Declare function with = function() { }
Use delete keyword to delete variable

Statement Review
 Use coding style
functionNamesLikeThis;
variableNamesLikeThis;
ConstructorNamesLikeThis;
EnumNamesLikeThis;
methodNamesLikeThis;
SYMBOLIC_CONSTANTS_LIKE_THIS;
extract from Google Closure Library Style Guide
 Always put brachet on statement and space on test
if ( test ) {
/* something to do */
}

 Forget eval function you are going wrong !

 Max 3 level of indentation otherwise it means you are going wrong
extract from Linux Kernel Coding Style
 Strip whitespace and always use 4 spaces as tab spacing
 Use triple equality test === to avoid implicit type coercion Basics

Battle against Coding Horror
 Split big JS file into multiples files

 name your file regarding the namespace
/namespace/namespace.Class.js

 Use Namespace Pattern to group your Classes & Object
Instances

var namespace = namespace || {};
namespace.instance = new namespace.Class;

 Max target size of lines should be lower than 250
Basics

Let’s go

 Decide to look code around you and try
to apply 3 recommandations a week
 Have Fun !

To be continue… Fundamental JS

Basics

JS Basics

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