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jquery add, delete, modify and check instructions

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Release： 2023-05-12 12:10:08

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JQuery is a popular JavaScript library used to simplify and speed up the process of writing JavaScript code and is often used to create dynamic web pages and web applications.

In this article, we will learn about JQuery's add, delete, modify and query instructions, which allow you to easily implement CRUD operations (add, retrieve, update, delete).

1. Add (Create)

In JQuery, use the .append() method to add new elements to the web page. In the example below, we will add a new paragraph element using JQuery.

$("body").append("<p>这是一个新的段落。</p>");

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This command will search the entire HTML for the <body> element and add a new paragraph within that element. You can remove the body element and use a different selector if needed.

2. Retrieve(Retrieve)

In JQuery, we use selectors to find specific elements. In the example below, we will use a selector to find all  elements and change their background color to red.

$("p").css("background-color", "red");

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This directive will find all  elements and change their background color to red. You can use other selectors to find the element you need to change.

3. Update

In JQuery, we can use the .text() or .html() method to change elements text content or HTML content. The following example will use the selector to find all <h1> elements and change their text to "New Title".

$("h1").text("新标题");

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This directive will find all <h1> elements and change their text to "New Title". You are free to change the text or HTML content of the element.

4. Delete

In JQuery, we can use the .remove() method to delete elements from the web page. The following example will use a selector to find all <img> elements and remove them from the document.

$("img").remove();

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This directive will find all <img> elements that match the selector and remove them from the HTML document. You can remove other elements as needed.

Summary

In this article, we have learned about JQuery's add, delete, modify and query instructions. Their operation is very simple and easy to understand. By using these instructions, you can easily implement CRUD operations. Don't forget to use these directives in your next JQuery project!

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