JavaScript Advanced Programming (3rd Edition) Notes-Chapter 1th-javascript Introduction

PS: The first chapter of the content is not much, the previous days to read the records collated a bit, first sent up.

A brief history of 1.1 JavaScript

1, JavaScript was born to deal with this simple form verification.

1.2 JavaScript Implementation

1, the complete JavaScript composition:

Core (ECMAScript): Provide core language functions;

Document Object Model (DOM): Provides methods and interfaces for accessing and manipulating Web page content;

Browser object Model (BOM): Provides methods and interfaces for interacting with the browser.

2. A Web browser is one of the possible hosting environments for implementing ECMAScript implementations.

3. The ECMA-262 standard specifies the components of the JavaScript language: syntax, type, statement, keyword, reserved word, operator, object.

4, ECMAScript Compatibility: Compatibility is a headache for developers, but also the reason why the language is really popular.

5. Fundamentally, the BOM only handles browser windows and frames; but it is customary to count all browser-specific JavaScript extensions as part of the BOM. Here are some of these extensions:

A) popup The function of the new browser window;

b) The ability to move, zoom, and close the browser window;

c) Navigator object that provides browser details;

d) A Location object that provides detailed information about the pages loaded by the browser;

e) A Screen object that provides detailed information about the user's display resolution;

f) support for cookies;

g) Custom objects such as the activexobject of XMLHttpRequest and IE.

6, BOM no standard can be followed, so each browser has its own implementation.

"END"

JavaScript Advanced Programming (3rd Edition) Notes-Chapter 1th-javascript Introduction