Getting Started with JavaScript

JavaScript is a scripting language, a dynamic type, a weak type, and a prototype-based language.

Features:

Loose, weak type

JavaScript variables do not have to have a definite type, which is very different from the language you learned earlier.

Object Properties

Its object is to put Shu

Based on prototypes

Its object-oriented inheritance mechanism is prototype-based. A prototype prototype is an object that other objects can use to implement property inheritance. The benefit of using it is to have all object instances share the properties and methods that it contains. In JS, only inheritance is supported and interface implementations are not supported.

composition

A completed JavaScript consists of three parts:ecmascript,dom and BOM.

1)ECMAScript

An open, internationally accepted scripting language specification.

It is not a scripting language in itself. JavaScript is an implementation of the ECMASCRIPT specification.

2)DOM--Document Object model

Document Object model,d (Web document), O (object), M (model, tree structure)

is for API interface, depicts a hierarchical node tree.

3)bom--Browser object Model

It provides a number of objects for accessing the functionality of the browser.

The relation and difference between BOM and Dom

The BOM lacks the specification, itself does not have the standard or the organization to standardize it, but the DOM has become the world standard, has three grades DOM1, DOM2, DOM3.

The most fundamental object of the BOM is window, the most fundamental object of the DOM is document. The relationship is actually a BOM containing the DOM.

Summary: From CSS to HTML, to XML, js,b/s this part of the content or a piece of it again, just in the implementation of a simple small example. But if two kinds of interactions are involved, such as js+html or js+jquery, it is more difficult. But before the beef brisket, although looking very complex, but still have a sense of familiarity. Come on, let's go!

Getting Started with JavaScript