The Web front-end development--JS Technology Big Comb

What is JS

JavaScript is a literal-translation scripting language, which is a dynamic type, a weak type, a prototype-based language, and a built-in support type. Its interpreter is called

For the JavaScript engine, a part of the browser that is widely used in the client's scripting language. JavaScript is a kind of object-oriented capability, the solution

The programming language of the release type. More specifically, it is a client-side scripting language that is Object-and event-driven and has relative security. Because he doesn't need it.

Run in a language environment and only need to support its browser. Its main purpose is to verify the data sent to the server side, increasing the web

and enhance user experience.

The following JS from the overall perspective of the JS knowledge points to comb a bit.

Next, let's introduce two important objects.

DOM Object

The HTML DOM is the standard (the English abbreviation for the HTML Document Object model, document object models for HTML). HTML DOM

Defines a series of standard objects for HTML, as well as a standard way to access and manipulate HTML documents. Through the DOM, you can access all the HTML

Elements, along with the text and attributes they contain. You can modify and delete the content, and you can also create new elements.

When a Web page is loaded, the browser creates a Document object model for the page.

The HTML DOM model is constructed as a tree of objects.

BOM Object

The BOM is also called the browser object model, which provides many objects for accessing the functionality of the browser. BOM is missing specification, and each browser provider

Expanding it according to your own ideas, the browser's common object becomes the standard of fact. Therefore, the BOM itself is no standard, or there is no group

Weaving to standard it.
BOM objects include:

1.window object. The core object of the BOM. A global variable is a property of a Window object, and a global function is a method of a Window object .

2.location object. Provides information about the documents loaded in the current window, as well as some navigational features.

3.history object. It keeps a record of the user's Internet access, from the moment the window is opened.

The role of JS:

Read and write HTML elements and embed dynamic text in HTML pages.

Responds to browser events to validate data before it is committed to the server.

Detects visitor's browser information. Control of cookies, including creation and modification.

Personal finishing touches

If the feeling of CSS is the interface of the beautification, then JS so that the interface can dance, JS not only can dynamically manipulate HTML, but also dynamically add

or change the style of CSS, reasonable use of JS will make the page more vivid, can express a very powerful effect. combination of static and dynamic, make the webpage more spiritual

Live Beautiful.

The Web front-end development--JS Technology Big Comb