What is JavaScript_Basics

What is JavaScript
JavaScript is an object- and event-driven client-side scripting language.
JavaScript was originally designed to check the correctness of HTML form input.
JavaScript originated from Netscape’s LiveScript language.

History of JavaScript
JavaScript originally originated from the LiveScript language. When the Internet became popular, more and more websites began to use HTML forms to interact with users. However, form interaction became This has eliminated a major bottleneck that restricts the development of the network (users always wait painfully for data to be transmitted to the server for detection and whether it is correct or not. Mere form detection results in multiple client-server interactions). So Netscape launched the LiveScript language, and finally Netscape and Sun named LiveScript JavaScript (JAVA was a very fashionable Internet term at the time). Then Microsoft started its ambitious browser plan and launched JScript, and then appeared on the Internet. There are several similar JavaScript languages, but there are no unified features and syntax (JavaScript development at that time was regarded as a nightmare, so many programmers were not optimistic about JavaScript). Finally, JavaScript was submitted to the European Computer Manufacturers Association (ECMA). As a neutral ECMA, it began the road to standardizing the scripting language and named it ECMAScript.

Composition of JavaScript
Complete JavaScript is composed of ECMAScript (syntax), Browser Objects (DOM, BOM) (features).


The picture above is a diagram of the composition of JavaScript, and the arrows represent the calling relationships


A few questions
Why should you learn JavaScript?
Because you have no choice, only JavaScript can control all commonly used browsers, and JavaScript is one of the most important programming languages ​​in the world. To learn web technology, you must learn JavaScript.
JavaScript is a beautiful language, it’s good, so we have to learn it :)
Is JavaScript the same as Java?
Javascript has nothing to do with Java. They are two languages ​​in themselves. They have similar names, mainly for business reasons.

javascript is a client-side scripting language
java is a server-side language. (It is a product of SUN.)
Is JavaScript difficult to learn?
It’s not difficult. Getting started with JavaScript is very simple. You only need to have studied primary school mathematics to learn JavaScript well, but you must first learn the HTML language well.

What can JavaScript do?
JavaScript can detect the correctness of the form, implement Ajax, read, write, and change the structure DOM of the HTML page, respond to events, detect the device used by the viewer, and produce cool and dazzling web page effects. DHTML etc.
What software is needed to learn JavaScript?
All you need is Windows Notepad and a browser (IE, Firefox, Opera), but I recommend you to use the powerful Notepad editor.