Javascript explainedfor Java developers

Javascript is the “de facto” standard of the Web today

still… many of the developers are coming from the Java world

Javascript ecosystem evolves more dynamically

… than what Java devs are used to

Javascript script syntax has nothing to do with Java except that is looks familiar

Javascript execution environment is completely different from Java envs

Javascript community was built mainly by millennialsJava is getting old

Types

String, no char

Number, no int

Object

Array, Function (both are objects)

Type Typeof

Object ‘object’

Function ‘function’

Array ‘object’

Number ‘number’

String ‘string’

Boolean ‘boolean’

null ‘object’

Undefined ‘undefined’

Style

return{

ok: false};

return {ok: true

};

Operators

0 == ‘’ // true

0 == ‘0’ //true

‘’ == ‘0’ //false

Weird types, weird values

NaN === NaN //falseNaN !== NaN // true

typeof NaN // Numbertypeof null // Object

Falsy / Thruthy

falsenull

Undefined‘’0

NaN

var me = {name: ‘Jana’,age: 32,children: ‘Maybe some day’,pets: [{

name: ‘Baron’, species: ‘dog’

}]};

Java has classes, methods, constructors

Javascript has functions

Function is an object(actually with each function declaration we create couple of objects )

Every Function can have methods

Functions better NOT be declared in if or for statements

Function scope demo

Javascript, in Crockford’s own words, it’s conflicted in its nature

functional language with dynamic typing and prototypal inheritance

Inheritance demo

AngularJs MVW framework

HTML augmentation, both ways binding, templating

Single page applications, rich and fluid UI’s

AnuglarJs demo

Javascript ecosystem

Javascript frameworks

Javascript tools

proprietary frameworks vs. open source

exhaustive manuals vs. github docs and cheat sheets

expensive trainings vs. quick and available MOOC

Thank you!