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Destructuring

Object Property - Shorthand Notatin​

var language = 'Markdown';
var extension = 'md';
var fileName = 'Destructuring';

var file = {
    language: language,
    extension: extension,
    fileName: fileName
}

// equivalent
var file = {language, extension, fileName}

Some Destructuring examples​

tip
Example One : deconstructoring object
let user = {
    name        : 'Ashley',
    email       : 'ashley@ilovees2015.net',
    lessonsSeen : [ 2, 5, 6, 7, 9 ],
    nextLesson  : 10
}

let { email, nextLesson } = user
tip
Example Two : deconstruring array
let [a, b] = [5, 3]
[a, b] = [a + 1, b + 1]
console.log( a, b ) // a = 6; b = 4

Deeper Destructuring​

let user = {
    name: 'Jonathan',
    age : 40,
    family : {
        wife : "Erin",
        kid : 'Meara'
    }
}

let {
        family:{
            wife
        }
    } = user

// console.log(family.wife) // error: family is not defined.
console.log(wife) // this is the right way to use.

Pitfalls​

danger

Writing an error property name of the deconstructoring object.

let { neme } = user
console.log( neme ) // actually it's name not neme, so it will raise an error.
danger

The destructuring object can not be null or undefined

let testUser = null
let { name, email } = testUser // error