Please describe what are the JavaScript language features?

JavaScript language features include: 1. Interpreted execution script language; 2. Object-based script language; 3. Simple weakly typed script language; 4. Relatively safe script language; 5. Event-driven script language; 6. Cross-platform scripting language.

The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.

(1).A scripting language for interpretive execution.

Like other scripting languages, JavaScript is also an interpreted language, which provides a very convenient development process. The basic structure of JavaScript's syntax is very similar to C, C++, and Java. But unlike these languages, which need to be compiled before use, they are interpreted line by line while the program is running. JavaScript is combined with HTML tags to facilitate user operations.

(2). An object-based scripting language.

It can also be considered an object-oriented language, which means that JavaScript can work with objects it has already created. Therefore, much functionality can come from the interaction of methods of objects in a scripting environment with scripts.

(3). A simple weakly typed scripting language.

Its simplicity is mainly reflected in: First of all, JavaScript is a simple and compact design based on Java's basic statements and control flow, which makes it easier for users to learn Java or other C language programming. The language is a very good transition, and for programmers with C programming skills, JavaScript is also very easy to get started; secondly, its variable types are weakly typed and do not use strict data types.

(4). A relatively safe scripting language.

As a security language, JavaScript is not allowed to access the local hard disk, and cannot store data in the server. It is not allowed to modify and delete network documents. Information can only be realized through the browser. Browse or interact dynamically. This effectively prevents data loss or illegal access to the system.

(5). An event-driven scripting language.

JavaScript responds to users in an event-driven manner. The action generated by performing a certain operation on a Web Page is called an "Event". For example, pressing the mouse, moving the window, selecting the menu, etc. can be regarded as events. When an event occurs, it may cause a corresponding event response and execute certain corresponding scripts. This mechanism is called "event-driven".

(6). A cross-platform scripting language.

JavaScript depends on the browser itself and has nothing to do with the operating environment. As long as the computer can run the browser and the browser supports JavaScript, it can be executed correctly, thus realizing "write once and travel around the world" "dream.

Therefore, JavaScript is a new description language that can be embedded in HTML files. The JavaScript language can respond to user demand events (such as form input) without requiring any network transmission of data back and forth. Therefore, when a user inputs a piece of data, the data does not need to be sent to the server for processing and then sent back, but can be directly processed by the client's application.

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