A brief introduction to JavaScript and its features

JavaScript is a scripting language that is object-based (object) and event-driven (driven) and has a secure performance. It is intended to be used with HTML Hypertext Markup Language, Java scripting language (Java applets) to connect multiple objects in a Web page, interacting with web customers. So that you can develop client applications, and so on. It is implemented by embedding or entering into a standard HTML language. Its appearance compensates for the HTML language flaw, it is the Java and the HTML compromise choice, has the following several basic characteristics:

1, is a scripting language

JavaScript is a scripting language that uses small program segments to implement programming. Like other scripting languages, JavaScript is also an interpretive language that provides an easy development process. Its basic structure form and C, C + +, VB, Delphi is very similar. But unlike these languages, it needs to be compiled first, and is interpreted step-by-step in the process of running a program. It is combined with HTML tags to facilitate user action.

2, object-based language.

JavaScript is an object-based language that can be viewed as an object-oriented object. This means that it can use the objects that you have created. As a result, many features can be derived from the interaction of the methods and scripts of objects in the scripting environment.

3. Simple Nature

The simplicity of JavaScript is mainly reflected in: first of all, it is a simple and compact design based on Java basic statements and control flow, which is a very good transition for learning java. Second, its variable type is weakly typed and does not use a strict data type.

4. Safety

JavaScript is a security language that does not allow access to local hard disks, does not store data on the server, modifies and deletes network documents, and can only be accessed through browser or dynamic interaction. So as to effectively prevent the loss of data.

5, dynamic nature of

JavaScript is dynamic and can respond directly to user or customer input without having to go through a Web service program. It responds to the user's response in an event-driven manner. Event-driven, which is the action generated by performing an action in the home page, is called an event. For example, press the mouse, move the window, select the menu, etc. can be considered as an event. When an event occurs, the corresponding event response may be caused.

6. Cross-platform nature

JavaScript is dependent on the browser itself, regardless of the operating environment, as long as the browser can run the computer, and support JavaScript browser to execute correctly. Thus realizing the "write once, all over the world" dream. In fact, the best thing about JavaScript is that you can do a lot of things with very small programs. No need for high-performance computers, software only need a word processing software and a browser, without the Web server channel, through their own computer can do everything.

The combination of JavaScript is a new descriptive language that can be embedded in HTML files. The JavaScript language can respond to consumer needs events such as: form, instead of using any network to transmit data back and forth, so when a user enters a piece of data, it does not have to pass through to the server to process, then pass back the process, and directly by the client ( Client) are processed by the application.