Detailed explanation of jQuery's method of adding and deleting DOM elements_jquery

This article analyzes the jQuery method of adding and removing DOM elements. Share it with everyone for your reference, the details are as follows:

Introduction

DOM is the abbreviation of Document Object Modeule. Generally speaking, DOM operations are divided into three aspects.

1. DOM Core

DOM Core is not exclusive to javascript. Any programming language that supports DOM can use it. Its uses are far beyond just web pages. It can also be used to process any document written using markup language, such as XML.
For example: document,getElementsByTagName("form"); //Use DOM Core to get the form object.

2. HTML-DOM

When using Javascript and DOM to write scripts for HTML files, there are many attributes that belong to HTML-DOM. HTML-DOM appeared even earlier than DOM Core. It provides some more concise notations to describe various HTML The element's properties.
For example:

Copy code The code is as follows:

document.forms //HTML-DOM provides a forms object.

PS: It can be seen that obtaining objects and attributes can be implemented using DOM Core or HTML-DOM.

3. CSS-DOM

CSS-DOM is an operation for CSS. In JavaScript, the main function of CSS-DOM is to obtain and set various attributes of the style object, so that the web page can present various effects.

For example:

Copy code The code is as follows:

element.style.color="red";//Settings Method to set the font color of an element.

Common methods

1. Find element node

Copy code The code is as follows:

var $li = $("ul li:eq(0)");/ /Get the first li under the ul tag, which can also be written as $("#ulID li:eq(0)");

2. Find element attributes

Use jquery's attr() method to obtain the values ​​of various attributes of the element. The parameter of the attr() method can be one or two.

When the parameter is one, it is the name of the attribute to be queried.

When there are two parameters, you can set the value of the attribute.

alert($("#id").attr("title")); //输出元素的title属性.一个参数
$("#id").attr("title","改变title值"); //改变元素的title属性值.二个参数

3. Add element node

$(html) To briefly explain, the $(html) method will create a dom object based on the incoming html tag string, and package the dom object into a jquery object and return it. In short, it will put all the html code of the tag. Just go to the $() factory!

Example:

var $htmlLi = $(" <li title='香蕉'>香蕉</li>"); //创建DOM对象
var $ul = $("ul");  //获取UL对象
$ul.append($htmlLi); //将$htmlLi追加到$ul元素的li列表

Listed below are some methods of inserting nodes

Method	Description	Example
Append()	Append content to each matching element	HTMLCode JQueryCode $(“ul”).append(“ AA ”); Results AA
appendTo()	This method is opposite to Append(). a.Append(b) is to replace b is appended to a, and appendTo() is to append b pursues a in	HTMLCode JQueryCode $ (“ AA ”).appendTo (“ul”).; Results AA
Prepend()	Prepend content inside each matched element	HTMLCode Haha JQueryCode $(“p”).prepend(“ABC”); Results ABC Haha
prependTo()	This method is opposite to Prepend(). a. Prepend (b) is to replace b is prepended to a, and prependTo () is to prepend b is prepended to a in	HTMLCode Haha JQueryCode $(“ABC”).prependTo.(“p”); Results ABC Haha
After()	inserts content after each matched element, is after	HTMLCode AAA JQueryCode $(“p”).After(“cc”); Results AAA cc
insertAfter()	is the opposite of After()	HTMLCode AAA JQueryCode $ (“cc”).After(“p”); Results AAA cc
Before()	Insert content before each matching element	HTMLCode AAA JQueryCode $(“p”). Before (“cc”); Results cc AAA
insertBefore()	is the opposite of Before()	HTMLCode AAA JQueryCode $ (“cc”). insertBefore (“p”); Results cc AAA

好了，不要斋看，自己动手试试吧:)

4.删除元素节点

由于我们需要经常动态去改变DOM元素，因此Jquery提供了两种删除节点的方法，即remove()和empty();

4.1 remove()方法

$("p").remove();// 我们可以获取到要删除的元素，然后调用remove()方法
$("ul li:eq(0)").remove().appendTo("ul");// 删除ul下面的第一个li标记，然后再把删除的li标记重新加到ul里面，remove()方法返回删除元素的引用，这时你可以继续使用
$("ul li").remove("li[title!=ABC]");//remove可以接受通过参数来选择性的删除符合条件的元素;

4.2 empty()方法

严格来讲，empty()方法并不是删除元素，而是清空

例：

HTML代码：

<ul>
<li title="AAA">AAA</li>
</ul>

JQuery代码：

复制代码 代码如下:

$("ul li:eq(0)").empty();

结果

<ul>
<li title="AAA"></li>
</ul>

记住，只会清空内容，不会请空属性;

更多关于jQuery操作DOM元素相关内容感兴趣的读者可查看本站专题：《jQuery操作DOM节点方法总结》

希望本文所述对大家jQuery程序设计有所帮助。