Shulou(Shulou.com)05/31 Report--

This article introduces the relevant knowledge of "how to realize Dom programming with Javascript". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Javascript Dom programming

One: Document Object Model

In the DOM model, each element (element), attribute (attribute), and text (text) can be regarded as an object. Javascript can access these objects independently, and these objects can be found and changed in some ways.

DOM states that the label of each HTML is an element node, the text contained in the element is a text node, and each HTML attribute is an attribute node.

Two: access the node of DOM

A: get elements through ID

Vartarget=document.getElementById ("berenger")

B: get elements through TagName

VarlistItems=document.getElementsByTagName ("li")

ListItems is an array-like object, and you can use listItems.Length to get the length of the object.

C: get elements through ClassName

In most cases in Javascript Dom programming, it is easier to use className to get elements than tagname, but dom does not provide a corresponding function, so we will create a method.

Can be broken down into the following three steps:

1: search for all elements in the document.

2: for each element, compare the class you belong to with the class you are looking for.

3: if the same, add it to the list.

The js code is as follows:

VarCore= {}; Core.getElementsByClass=function (theClass) {varelementArray= []; / IE does not support getElementsByTagName ("*"), use document.All. If (document.all) {elementArray=document.all;} else {elementArray=document.getElementsByTagName ("*");} varmatchedArray= []; varpattern=newRegExp ("(^ |)" + theClass+ "(| $)"); for (vari=0;i

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