"JavaScript"--macro control

JavaScript, which was born in 1995, was designed to verify the validation of form input (in client-side validation, lighten the burden on the server), and has evolved into a feature that enhances web interaction and can enhance the user's experience.

One, JavaScript definition:JavaScript is a dynamic type, weak type, built-in support type, prototype-based scripting language.

Second, JavaScript mapping analysis

Three, the analysis of the guide map

JavaScript features

1, scripting language: JavaScript is an explanatory script language, C, C + + and other languages are compiled and executed, and JavaScript is in the process of running a line of interpretation. (c or C + + generates code to compile, generate the appropriate DLL or document, so that the machine can be recognized, and JavaScript code embedded in the HTML, when the program runs the browser will be interpreted line by row)

2. Object-based: JavaScript is an object-based scripting language that can not only create objects, but also use existing objects. The syntax syntax for creating an object is as follows.

             var box = new Object (); New mode             var box = Object ();     The New keyword             var box =[] is omitted;            Using the literal way, so simple

3, Dynamic: JavaScript is an event-driven scripting language that does not require a Web server to respond to user input. When you visit a webpage, the mouse clicks or moves up and down the page, and the window moves, and so on, JavaScript can respond directly to these events.

4, cross-platform: JavaScript scripting language is not dependent on the operating system, only requires browser support. So a JavaScript script can be used on any machine after it is written, as long as the browser on the machine supports the JavaScript scripting language, JavaScript is now supported by most browsers.

5, simple: JavaScript language is used in the weak type of variable type, the use of the data type is not strict requirements, is based on the Java Basic statement and control of the scripting language, its design is simple and compact. (similar to the syntax of Java, such as flow control statements, operators, etc.), the following are the syntax for declaring a string variable, a number variable, and a Boolean variable.

           var a= ' I am a string ';   A is a string variable           var b=20;                 b is a number variable           var c =true;              C is a Boolean variable

The core composition of JavaScript

1. ECMAScript: Describes the syntax and basic objects of JavaScript.

2. Document Object Model (DOM): Describes methods and interfaces for handling Web page content.

3. Browser object Model (BOM): Describes the methods and interfaces that interact with the browser.

Third, summary

JavaScript is a client-side scripting language, beginners JavaScript, starting with its syntax, that is, starting from ECMAScript, because the previous study of VB and C #, so it is not very difficult to learn, and later I will summarize its DOM and BOM.

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"JavaScript"--macro control