Js contains implementation code

To be compatible with IE and FF, we have to use the following methods: <Meta charset = "UTF-8"> <meta name = "keywords" content = "dom contains METHOD by SITU zhengmei"> <meta name = "description" content = "dom contains method situ zhengmei "> <br/> contains method <p> <strong id =" child "> contains method </strong> </p> <p>
[Ctrl + A select all Note: If you need to introduce external Js, You need to refresh it to execute]

However, Firefox supports the compareDocumentPosition () method, which is developed by W3C and supported by standard browsers. However, it is not practical, so no one can use it and cannot be promoted. Its usage is similar to that of contains, but the returned value is not a Boolean value, but a very strange value. It is calculated in the following way:

Bits	Number	Meaning
000000	0	Element consistency
000001	1	Node in different documents (or one out of the document)
000010	2	Node B is before node.
000100	4	Node A is before Node B.
001000	8	Node B contains node
010000	16	Node A contains Node B
100000	32	Private Use of browsers

<Meta charset = "UTF-8"> <meta name = "keywords" content = "dom contains METHOD by SITU zhengmei"> <meta name = "description" content = "dom contains method situ zhengmei "> <br/> compareDocumentPosition method <p> <strong id =" child "> This example runs in a standard browser. </Strong> </p> <p>
[Ctrl + A select all Note: If you need to introduce external Js, You need to refresh it to execute]

PPK provides the following solutions.Copy codeThe Code is as follows: if (window. Node & Node. prototype &&! Node. prototype. contains ){
Node. prototype. contains = function (arg ){
Return !! (This. compareDocumentPosition (arg) & 16)
}
}

I made a shorter one:Copy codeThe Code is as follows: if (!! Window. find ){
HTMLElement. prototype. contains = function (B ){
Return this. compareDocumentPosition (B)-19> 0
}
}

<Meta charset = "UTF-8"> <meta name = "keywords" content = "dom contains METHOD by SITU zhengmei"> <meta name = "description" content = "dom contains method situ zhengmei "> <br/> contains method <p> <strong id =" child "> contains method </strong> </p> <p>
[Ctrl + A select all Note: If you need to introduce external Js, You need to refresh it to execute]

Copy codeThe Code is as follows: // 2011.9.24 by SITU zhengmei
Var contains = function (root, el ){
If (root. compareDocumentPosition)
Return root = el | !! (Root. compareDocumentPosition (el) & 16 );
If (root. contains & amp; el. nodeType = 1 ){
Return root. contains (el) & root! = El;
}
While (el = el. parentNode ))
If (el = root) return true;
Return false;
}