How to add custom method in jQuery

With the continuous development of front-end technology, more and more websites are beginning to use dynamic effects to enrich the user interface. jQuery is a very popular JavaScript library that simplifies manipulation of DOM, events, AJAX, etc., and provides many convenient methods and functions to quickly create dynamic effects. On this basis, jQuery allows users to add custom methods to quickly call when needed. This article will introduce how to add custom methods in jQuery.

1. What is a jQuery custom method?

The jQuery custom method means that developers use the jQuery.fn.extend() method to add a custom function to the jQuery object. The jQuery.fn.extend() method merges the contents of one or more objects into the target object. The target object here is jQuery.fn, the prototype object of jQuery, which is shared by all jQuery instances. Therefore, once you add a custom function on jQuery.fn, all jQuery instances can use it by calling this function.

2. How to add a custom method

To add a custom method in jQuery, you can follow the following steps:

1. Write a custom function

First, write a custom function. This function can complete the required functions and accept some parameters. Here, we define a simple function that can convert all the text content of a group of elements into uppercase letters:

function toUpperCase() { return this.each(function () { var text = $(this).text(); $(this).text(text.toUpperCase()); }); }

This function uses the each method provided by jQuery and traverses each element that calls it. , and converts all text of each element to uppercase letters.

2. Add a custom method

Next, use the jQuery.fn.extend() method to add a custom function to the jQuery object. Assume that you want to name the custom function "toUpperCase", you can write it like this:

$.fn.extend({ toUpperCase: function () { return this.each(function () { var text = $(this).text(); $(this).text(text.toUpperCase()); }); } });

The jQuery.fn.extend() method is used here, and the object literal is passed in. This object literal starts with "toUpperCase" " is the key, and the custom function written before is passed in the value. In this way, we have successfully added a custom method to jQuery.

3. How to call a custom method

After adding the custom method, we can call it like other jQuery methods. Suppose we have the following HTML page:

 
 
Hello, world!
 
This is a paragraph.
 
 
list item 1
 
list item 2
 
list item 3
 
 
 

Now we want to convert all text content within the element with class "content" to uppercase letters, which can be written like this:

$(".content").toUpperCase();

This call will convert the text content of "Hello, world!", "This is a paragraph.", and all list items to uppercase letters.

4. Summary

This article introduces how to add custom methods in jQuery. First, we write a custom function and then add it to the jQuery object using the jQuery.fn.extend() method. Finally, we demonstrated how to call custom methods and implement some simple functions. Through this method, we can add more custom methods to jQuery to develop dynamic web pages more conveniently and quickly.

The above is the detailed content of How to add custom method in jQuery. For more information, please follow other related articles on the PHP Chinese website!