Home Web Front-end Front-end Q&A How to solve jquery selected not changing problem

How to solve jquery selected not changing problem

Apr 17, 2023 am 11:28 AM

When developing websites, we often use jQuery to manipulate DOM elements. One common operation is to select elements and modify their properties or content. In jQuery, you can use selectors to select elements that need to be operated. However, sometimes we find that although elements have been selected through the selector, modifying their attributes or content does not take effect. So, how to solve this situation?

Case Demonstration

Let us look at a simple case to better understand the problem. Below is an HTML file that contains some paragraphs and buttons:

<!DOCTYPE html>
<html>
<head>
    <title>jQuery selected没有改变</title>
</head>
<body>
    <p id="para1">Hello World!</p>
    <p class="para2">jQuery is awesome!</p>
    <button id="btn1">改变段落内容</button>
    <button id="btn2">改变按钮文本</button>

    <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
    <script>
        $(document).ready(function(){
            $("#btn1").click(function(){
                $("#para1").text("Paragraph 1内容已改变!"); //改变段落1的内容
            });

            $("#btn2").click(function(){
                $(".para2").text("Paragraph 2内容已改变!"); //改变所有class为para2的段落的内容
            });
        });
    </script>
</body>
</html>
Copy after login

As you can see, in this case, we used jQuery to select two elements. One is the paragraph with the ID "para1", and the other is all the paragraphs with the class "para2". We're trying to use jQuery to modify the content of the buttons when they are clicked.

Cannot change content

However, when we run the example and try to change the content of the paragraph to the new value, we find that there is no change.

There are a few possible reasons here:

  1. There is a spelling error in the code that prevents the code from executing as expected.
  2. The selector does not select the actual element.
  3. The code attempts to change a property or property value that cannot be changed.

If this problem occurs, we can use the browser's developer tools to check the cause of the problem.

Debug Code

In this example, open your browser's developer tools (press F12) and select the "Elements" tab in the HTML code. In this tab, you can view the values ​​of DOM elements as well as CSS properties.

We will see that the value in the first paragraph has not been modified correctly, but is still "Hello World!", and the content of the second paragraph has not been modified to "Paragraph 2 content has been changed." Change!". This means we need to check selectors and code.

Check the selector

First, check whether the selector selects the correct element. In this example, we use two selectors: an ID selector and a class selector. Use the # symbol in the selector to represent the ID selector, and use the . symbol to represent the class selector.

For example, the selector "#para1" will select the element with the id "para1"; the selector ".para2" will select all elements with class "para2".

Make sure there are no errors in the selector.

Check the code

Next, check whether the code is correct. In this example, we are trying to modify the content of the paragraph in the handler of the button click event. We use jQuery's .text() method to modify the content of the paragraph.

For example, $("#para1").text("Paragraph 1 content has changed!"); will select the paragraph with the element ID "para1" and change its text to "Paragraph 1 content has been changed!" Change!".

Make sure the code calls the correct methods and properties and has no syntax errors.

solve the problem

By inspecting the selector and code, we can discover the cause and solve the problem.

In this example, when we inspected the code, we found that the modification operation was not performed correctly. The reason is that we did not make the correct call when modifying the operation. We should use the following code:

$(document).ready(function(){
    $("#btn1").click(function(){
        $("#para1").text("Paragraph 1内容已更改!");
    });
 
    $("#btn2").click(function(){
        $(".para2").text("Paragraph 2内容已更改!");
    });
});
Copy after login

After correctly executing the above code, we reload the web page. Now, we find that it works fine and the content of the paragraph is successfully modified.

Summary

This article briefly introduces the problems that may arise when selecting elements and modifying their properties or content in jQuery. When a problem occurs, we should use the browser's developer tools to check the code and selectors to locate the cause of the problem. Only by checking and modifying the code can the problem be finally solved and the normal operation of the web page ensured.

The above is the detailed content of How to solve jquery selected not changing problem. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

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

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

React's Role in HTML: Enhancing User Experience React's Role in HTML: Enhancing User Experience Apr 09, 2025 am 12:11 AM

React combines JSX and HTML to improve user experience. 1) JSX embeds HTML to make development more intuitive. 2) The virtual DOM mechanism optimizes performance and reduces DOM operations. 3) Component-based management UI to improve maintainability. 4) State management and event processing enhance interactivity.

How do you connect React components to the Redux store using connect()? How do you connect React components to the Redux store using connect()? Mar 21, 2025 pm 06:23 PM

Article discusses connecting React components to Redux store using connect(), explaining mapStateToProps, mapDispatchToProps, and performance impacts.

How do you define routes using the <Route> component? How do you define routes using the <Route> component? Mar 21, 2025 am 11:47 AM

The article discusses defining routes in React Router using the &lt;Route&gt; component, covering props like path, component, render, children, exact, and nested routing.

What are the limitations of Vue 2's reactivity system with regard to array and object changes? What are the limitations of Vue 2's reactivity system with regard to array and object changes? Mar 25, 2025 pm 02:07 PM

Vue 2's reactivity system struggles with direct array index setting, length modification, and object property addition/deletion. Developers can use Vue's mutation methods and Vue.set() to ensure reactivity.

What are Redux reducers? How do they update the state? What are Redux reducers? How do they update the state? Mar 21, 2025 pm 06:21 PM

Redux reducers are pure functions that update the application's state based on actions, ensuring predictability and immutability.

What are Redux actions? How do you dispatch them? What are Redux actions? How do you dispatch them? Mar 21, 2025 pm 06:21 PM

The article discusses Redux actions, their structure, and dispatching methods, including asynchronous actions using Redux Thunk. It emphasizes best practices for managing action types to maintain scalable and maintainable applications.

What are the benefits of using TypeScript with React? What are the benefits of using TypeScript with React? Mar 27, 2025 pm 05:43 PM

TypeScript enhances React development by providing type safety, improving code quality, and offering better IDE support, thus reducing errors and improving maintainability.

React Components: Creating Reusable Elements in HTML React Components: Creating Reusable Elements in HTML Apr 08, 2025 pm 05:53 PM

React components can be defined by functions or classes, encapsulating UI logic and accepting input data through props. 1) Define components: Use functions or classes to return React elements. 2) Rendering component: React calls render method or executes function component. 3) Multiplexing components: pass data through props to build a complex UI. The lifecycle approach of components allows logic to be executed at different stages, improving development efficiency and code maintainability.

See all articles