The origin of JavaScript and what the browser consists of

As front-end developers, JavaScript is something we must learn and plays an important role in our work. Do you know its origin? So today I will talk to you about the origin of JS

1. Initial JavaScript

Mosaic was the first browser in the history of the Internet to commonly use and display images in 1993 come out.

Later, due to the transfer of trademark rights, the original development team developed Netscape Navigator, which is also the predecessor of many browsers.

JS first appeared in 1996 as part of the Netscape Navigator browser. It was originally designed to improve the user experience of web pages. The author is Brendan Eich.

At first JS was named liveScript, but later it was renamed JavaScript due to cooperation with Son Company. Later, Son Company was acquired by Oracle Company, and all copyrights belong to Oracle.

2. The composition of the browser

The browser mainly consists of two parts, the shell and the kernel (rendering engine (grammar rules and rendering) [js engine | other modules 】) part, the kernel also contains many things.

Rendering engine, the rendering engine in the kernel is mainly responsible for the html and CSS parts, defining grammar rules, rendering rules, rendering paths and speeds, etc.

Network, used to display the content of the request, such as http request, it has a platform-independent interface and can work on different platforms.

The UI backend is used to draw basic components such as combo selection boxes. It has a universal interface that is not specific to a certain platform. The bottom layer uses the user interface of the operating system.

js engine, ie6 was released in 2001, which realized the optimization of js engine for the first time.

In 2008, Google released Chrome, which uses an optimized js engine. The engine code is V8. It is famous for its fast speed because it can directly convert js code into machine code 0101 for execution.

Later, Firefox also launched a powerful js engine - Firefox3.5 tracemonkey (path optimization for frequently executed code) - Firefox 4.0 leaguermonkay.

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