Introduction to JavaScript document object
This article mainly introduces the introduction of JavaScript document object, which has certain reference value. Now I share it with everyone. Friends in need can refer to it
1. The document object is a window object The sub-object can be used directly, mostly used to obtain HTML page elements
2.document object properties
a) alinkColor active link color
b) linkColor Text link color
c) vlinkColor The text color of the document link that the user has observed
d) Cookie information stored in the client
①.Yes Some web sites store some of the user's information in small text files on the customer's hard drive
②. Cookies can record the user's user name, password, web pages browsed, length of stay, etc. It is convenient for users to operate again
③. The information in the cookie is stored in the form of "key-value" pairs; and its information can only be characters in URL encoding. If there is Chinese, the Chinese characters need to be converted, that is, on the client The stored cookie can only contain information composed of numbers and letters
④. If you want to delete the cookie, you can modify its date so that it will automatically expire
3.Document object method
a) Clear the specified document content--not recommended to use
①.docObj.clear()--no parameters, no return value
②.Close the document stream When the document stream is opened again, the document content will be automatically cleared
b) Close the document stream
①.docObj.close()--no parameters, no return value
②. After the page is loaded, this method will be automatically executed
③. When the write() method is called to dynamically generate the page, if there is no close() method, the system will wait forever
④. When it is a window When adding an onload event, the onload event will not be triggered without calling the close() method
c) Open the document stream
①.docObj.open([arg])--arg represents MIME type of output stream, default text/html; no return value
d) Write text to document
①.docObj.write(htmlStr)
②.Required Use close() to close the output stream after outputting the completed content; otherwise, the output content will be appended when the write() method is called again
e) Write the text into the document and wrap it in a new line
①.docObj .writeln(str)
The above is the entire content of this article. I hope it will be helpful to everyone’s study. For more related content, please pay attention to the PHP Chinese website!
Related recommendations:
Introduction to getters and setters in JavaScript
The above is the detailed content of Introduction to JavaScript document object. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











JavaScript is the cornerstone of modern web development, and its main functions include event-driven programming, dynamic content generation and asynchronous programming. 1) Event-driven programming allows web pages to change dynamically according to user operations. 2) Dynamic content generation allows page content to be adjusted according to conditions. 3) Asynchronous programming ensures that the user interface is not blocked. JavaScript is widely used in web interaction, single-page application and server-side development, greatly improving the flexibility of user experience and cross-platform development.

The latest trends in JavaScript include the rise of TypeScript, the popularity of modern frameworks and libraries, and the application of WebAssembly. Future prospects cover more powerful type systems, the development of server-side JavaScript, the expansion of artificial intelligence and machine learning, and the potential of IoT and edge computing.

Different JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.

JavaScript is the core language of modern web development and is widely used for its diversity and flexibility. 1) Front-end development: build dynamic web pages and single-page applications through DOM operations and modern frameworks (such as React, Vue.js, Angular). 2) Server-side development: Node.js uses a non-blocking I/O model to handle high concurrency and real-time applications. 3) Mobile and desktop application development: cross-platform development is realized through ReactNative and Electron to improve development efficiency.

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

This article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base

The shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.

JavaScript does not require installation because it is already built into modern browsers. You just need a text editor and a browser to get started. 1) In the browser environment, run it by embedding the HTML file through tags. 2) In the Node.js environment, after downloading and installing Node.js, run the JavaScript file through the command line.
