The composition of javascript and the role of each part

The core parts of JavaScript are: 1. ECMAScript (syntax and data types); 2. BOM (browser interaction, including DOM, events, windows); 3. DOM (web page document representation, which can operate and modify documents) ); 4. Auxiliary libraries (standard libraries and third-party libraries); 5. JavaScript engine (execute code, optimize performance).

The composition of JavaScript and the role of each part

JavaScript is a cross-platform scripting language, consisting of the following Core part consists of:

Core part

• ECMAScript:The core language specification of JavaScript, which defines the basic syntax and data types of the language .
• BOM (Browser Object Model):Provides the ability to interact with the browser, including DOM, events, window objects, etc.
• DOM (Document Object Model):Representation of web page documents, allowing scripts to operate and modify the document structure.

Auxiliary library

• Standard library:Provides common functions such as arrays, strings, and mathematical functions.
• Third-party libraries:Extensions provided by external developers that provide additional functionality such as charts, network requests, and data validation.

Engine

• JavaScript Engine:Responsible for executing JavaScript code. It compiles code into machine code and optimizes performance. Common JavaScript engines include V8 (Chrome), SpiderMonkey (Firefox), and JavaScriptCore (Safari).

The role of each part

ECMAScript:Specifies the syntax and behavior of JavaScript. It defines variables, functions, objects, and control flow structures.

BOM:Allows JavaScript to interact with the browser. It provides access to windows, documents, and browser native features.

DOM:Provides a way to programmatically manipulate web documents. Scripts can use the DOM to create, modify, and delete elements, as well as get and set properties.

Standard Library:Provides utility functions that allow developers to easily perform common tasks such as array operations, string manipulation, and mathematical calculations.

Third-party libraries:Extend the functionality of JavaScript, allowing developers to solve more complex problems such as data visualization, network interaction, and form validation.

JavaScript Engine:Execute JavaScript code and implement it as operations in the browser or runtime environment. It optimizes code and ensures fast execution.

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