How to implement specified assignment method using js and jQuery
Now I will share with you an article about js, jQuery and easyui to implement the designated value assignment method for the drop-down box. It has a good reference value and I hope it will be helpful to everyone.
js implementation:
#1. Select the i-th option by letting it be selected. The code is as follows: ( id is the drop-down box id)
(1) document.getElementById("id").options[i].selected=true;
(2) document.getElementById(" messagetoid").selectedIndex = 1; (Select the first option)
2. This is achieved by judging the value of the option. The code is as follows:
document.getElementById ("messagetoid").value=""; (Select the option whose value is empty)
jQuery implementation:
1. By selecting the i-th option, similar to 1 implemented in js, the code is as follows:
$("#id").get(0).selectedIndex =
1; (Select the first option)
2. By judging the value of the option, there are two methods. The code is as follows:
(1)$(" #id").val("123"); (Select the option with value "123")
(2)$("#messagetoid").attr("value", ""); (Select the option whose value is empty)
EasyUI implementation:
$('#id').combobox('setValue', 'A'); (Select the option whose value is A,)
The above is what I compiled for everyone. I hope it will be helpful to everyone in the future.
Related articles:
How to solve the practical problem of easyui date and time box ie compatibility (detailed tutorial)
Explain to you in detail Practical skills in Immutable and React
How to solve the error problem on VUEX compatible IE (detailed tutorial)
The value cannot be observed in Vuex What is the solution to change?
How to use readline in Node.js to read and write file contents line by line
How to use readline in Node.js Modules and util modules
Detailed explanation of using Node.js to write a simple command line tool (detailed tutorial)
In Node.js Use cheerio to make a simple web crawler (detailed tutorial)
How to implement parent components to pass multiple data to child components in vue
How to use Native in React to implement custom pull-down refresh to pull-up loaded list
The above is the detailed content of How to implement specified assignment method using js and jQuery. For more information, please follow other related articles on the PHP Chinese website!

Both Python and JavaScript's choices in development environments are important. 1) Python's development environment includes PyCharm, JupyterNotebook and Anaconda, which are suitable for data science and rapid prototyping. 2) The development environment of JavaScript includes Node.js, VSCode and Webpack, which are suitable for front-end and back-end development. Choosing the right tools according to project needs can improve development efficiency and project success rate.

Yes, the engine core of JavaScript is written in C. 1) The C language provides efficient performance and underlying control, which is suitable for the development of JavaScript engine. 2) Taking the V8 engine as an example, its core is written in C, combining the efficiency and object-oriented characteristics of C. 3) The working principle of the JavaScript engine includes parsing, compiling and execution, and the C language plays a key role in these processes.

JavaScript is at the heart of modern websites because it enhances the interactivity and dynamicity of web pages. 1) It allows to change content without refreshing the page, 2) manipulate web pages through DOMAPI, 3) support complex interactive effects such as animation and drag-and-drop, 4) optimize performance and best practices to improve user experience.

C and JavaScript achieve interoperability through WebAssembly. 1) C code is compiled into WebAssembly module and introduced into JavaScript environment to enhance computing power. 2) In game development, C handles physics engines and graphics rendering, and JavaScript is responsible for game logic and user interface.

JavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.

Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.

C and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.


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

SublimeText3 English version
Recommended: Win version, supports code prompts!

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

WebStorm Mac version
Useful JavaScript development tools

Dreamweaver CS6
Visual web development tools
