What is the javascript interpreter written in?

What is the Javascript interpreter written in?

Javascript is a very popular scripting language used for dynamic interactions in web pages and sending requests to the server. A Javascript interpreter is a program that converts Javascript code into code that a computer can understand and execute. So what is the Javascript interpreter written in? This article will delve into this issue.

Classification of Javascript interpreters

Before discussing what Javascript interpreters are written with, let’s first introduce the classification of Javascript interpreters. Javascript interpreters can be divided into two types: browser built-in Javascript interpreters and stand-alone Javascript interpreters.

Built-in Javascript interpreter in the browser

The built-in Javascript interpreter in the browser refers to the Javascript interpreter that comes with the browser. Among the common browsers, their built-in Javascript interpreters are:

• Chrome browser: V8 engine
• Firefox browser: SpiderMonkey engine
• Safari browser: JavaScriptCore engine
• Internet Explorer browser: Chakra engine

Different browsers choose different Javascript interpreters, the main reason is for performance and compatibility sexual considerations.

Stand-alone Javascript interpreter

A stand-alone Javascript interpreter usually refers to a Javascript interpreter that can be used in other applications, such as Node.js and Rhino. These Javascript interpreters can be used with other languages ​​and run on different operating systems.

Independent Javascript interpreter includes:

• Node.js: V8 engine
• Rhino: Mozilla Rhino engine
• SpiderNode: SpiderMonkey engine

What is the Javascript interpreter used to write?

Now back to the topic of this article, what is the Javascript interpreter used to write? The answer is that Javascript interpreters are usually written in C.

Specifically, Chrome and Node.js use the V8 engine developed by Google and are written in C. Firefox uses the SpiderMonkey engine developed by Mozilla and also written in C. Safari uses the JavaScriptCore engine, the bulk of which is also written in C. Internet Explorer uses the Chakra engine developed by Microsoft, also written in C.

C is a high-level programming language with powerful control capabilities and fast execution speed. Most operating systems support C compilers, and C has good cross-platform capabilities. Therefore, when writing a Javascript interpreter, using C allows developers to better control the execution process of Javascript code and improves the performance of the Javascript interpreter.

Implementation of Javascript interpreter

What actually happens when calling the Javascript interpreter? When executing Javascript code, the Javascript interpreter parses the code and executes it line by line. Specifically, the Javascript interpreter is implemented through the following steps:

1. Lexical parsing: Break down the Javascript code into a series of lexical elements, such as functions, variables, operators, etc.
2. Grammar parsing: Convert lexical elements into syntax trees to facilitate the execution of Javascript code.
3. Execution: The Javascript interpreter executes the Javascript code line by line according to the syntax tree and returns the calculation results to the calling program.

Summary

In this article, we took a deep dive into what Javascript interpreters are written in. We learned that Javascript interpreters are usually written in C because C can provide powerful control capabilities and fast execution speed. At the same time, the Javascript interpreter performs syntax and lexical analysis based on the Javascript code, then executes the Javascript code line by line, and finally returns the calculation results to the calling program.

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