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(, , ) . , , , . . , , :

function passByVal(arg1) {

var arg1 = 10;

}

var x = 5;

passByVal(5);

alert(x);

// 5,

function passByRef(arr1) {

arr1[0] = "NEW";

}

var y = ["first", "second"];

passByRef(y);

alert(y);

// NEW, second, ,

JavaScript : , , , . . , var .

window. , , window, undefined.

function myFunc() {

var x = "local";

y = "global";

}

myFunc();

alert(window.x);

// undefined

alert(y);

// global

alert(x);

//

JavaScript :

, Object;

JavaScript String ; Array ; Date ; Math ; Object ;

:

window ;

document , HTML-;

location , , URL;

navigator ;

history , ;

, HTML CSS JavaScript HTML CSS document, ;

, . . :

function Book() {

}

book :

var myBook = new Book();

, this. :

function Book() {

this.paper = true;

}

var myBook = new Book();

alert(myBook.paper);

// true, .. Book paper true

, .

function Book(isPaper) {

if (isPaper) this.paper = true;

else this.paper = false;

}

var myBook = new Book(false);

alert(myBook.paper);

// false

prototype, . :

Book.prototype.paper = false;

Book.prototype.isPaperBook = function() {

if (this.paper) alert("This is a paper book");

else alert("This is not a paper book");

}

function Book(isPaper) {

if (isPaper) this.paper = true;

}

var myBook = new Book(true);

myBook.isPaperBook();

// This is a paper book

, , paper false. , true.

- JavaScript

JavaScript - ( -) , .

:

var h = new Object();

h.property = 10;

alert(h.property);

, , 110:

var h = new Object();

h.property = 10;

h[0] = 100;

alert(h.property + h[0]);

, , h.property h[0] .

:

var h = new Object();

h.property = 10;

var s = 'ty';

alert(h['proper' + s]);

h['property'] , h.property.

delete:

var h = new Object();

h['property'] = 10;

alert(delete h['property']);

// true

alert(h['property']);

// undefined

:

var h = new Object();

...

var props = '';

for(var i in h)

props += i + ': ' + h[i] + '\n';

alert(props);

, i ,
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