Home > Web Front-end > JS Tutorial > body text

Detailed explanation of node operation methods such as each(), find() and filter() in jQuery (recommended)

高洛峰
Release: 2016-12-29 10:59:48
Original
1810 people have browsed it

1.each(callback)

Official explanation:

Return value: jQuery

Overview

Execute a function with each matching element as the context.

means that each time the function passed in is executed, the this keyword in the function points to a different DOM element (a different matching element each time). Moreover, every time the function is executed, a numeric value representing the position of the element as the execution environment in the matching element set is passed to the function as a parameter (an integer based on zero). Returning 'false' will stop the loop (just like using 'break' in a normal loop). Returns 'true' to jump to the next loop (just like using 'continue' in a normal loop).

Parameters

callback

Function to be executed for each matching element

Example

Description:

Iterate over two images and set their src attribute. Note: here this refers to the DOM object rather than the jQuery object.

HTML code:

jQuery code:

$("img").each(function(i){
this.src = "test" + i + ".jpg";
});
Copy after login

Result:

[ <img src="test0.jpg" />, <img src="test1.jpg" /> ]
Copy after login

2.find(expr|obj|ele)

Official explanation:

Return value: jQuery

Overview

Search for all elements that match the specified expression. This function is a great way to find out the descendant elements of the element being processed.

All searches rely on jQuery expressions. This expression can be written using CSS1-3 selector syntax.

Parameters

expr String
Expression used to find
jQuery object object
A jQuery object used to match elements
element DOMElement
A DOM element

Example

Description:

Start from all paragraphs and further search for span elements below . Same as $("p span").

HTML code:

Hello, how are you?

jQuery code:

$("p").find("span")
Copy after login

Result:

[ Hello ]

3.filter(expr|obj|ele|fn)

Official explanation:

Overview

Filter out matches that match the specified expression collection of elements.

This method is used to narrow the matching scope. Separate multiple expressions with commas

Parameters

expr String
String value, containing selector expressions for matching the current set of elements.
jQuery object object
Existing jQuery object to match the current element.
element Expression
A DOM element used to match elements.
function(index) Function
A function is used as a collection of test elements. It accepts a parameter index, which is the index of the element in the jQuery collection. In functions, this refers to the current DOM element.

Example

Parameter selector description:

Retain elements with select class

HTML code :

<p>Hello</p><p>Hello Again</p><p class="selected">And Again</p>
Copy after login

##jQuery Code:

$("p").filter(".selected")
Copy after login

Result:


[

And Again

]

The above is the each(), find() and filter() in jQuery introduced by the editor. I am waiting for the detailed explanation (recommendation) of the node operation method. I hope it will be helpful to everyone. If you have any questions, please leave me a message and the editor will reply to you in time. I would also like to thank you all for your support of the PHP Chinese website!


For more detailed explanations (recommended) of node operation methods such as each(), find() and filter() in jQuery (recommended), please pay attention to the PHP Chinese website!


Related labels:
source:php.cn
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
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn:Public welfare online PHP training,Help PHP learners grow quickly!