4. Set/get attribute nodes.
setAttribute();//Set
example:
var a = (“p”);
(“title”,”my demo”);
Regardless of whether there is a title attribute before, the subsequent value is my demo.
getAttribute();//Get
example:
var a =(“cssrain”);
var b = (“title”);
When obtaining, if the attribute does not exist, it returns empty, note that ie and ff return differently.
<body>
<p title="test">aaaa</p>
<p>bbbb</p>
<script type="text/JavaScript">
var paras = ("p");
for (var i=0; i< ; i++) {
var title_text = paras[i].getAttribute("title");
if (title_text != null) {
//There will be a problem when writing this way: ff only pops once, but ie is pops twice.
//If if (title_text != ") write like this, ie will only be popped once, but ff will be popped twice.
//What if I write this way? if (title_text) , we found that ie only pops up once, and ff only pops up once.
//if (title_text) is what we want.
//Note: If it does not exist, return null
//ie return “" ;
alert(title_text);
}
}
</script>
</body>
Although the return is different, it can be judged in one way.
if((“title”) ){
// do something
}
5,hasChildNodes:
You can know from the name, which is to determine whether the element has child nodes.
Returns the boolean type.
Text nodes and attribute nodes cannot have children, so their hasChildNodes will always return false;
hasChildNodes is often used with childNodes.
for example:
<body>
<div >
<div >a </div>
<div >b </div>
<div >c </div>
</div>
</body>
<script>
var ps = ("cssrain")
if(){
alert( );
}
</script>
Everyone should write by themselves, otherwise they would have poor memory just by looking at it.
Okay, let’s talk about this and I will continue to talk tomorrow.
Today I talked about using the dom method to delete nodes, replace nodes, find nodes, obtain attributes, etc. . .
The method of operating the DOM is almost the same.
Tomorrow we will talk about DOM attributes...
If you still don’t understand, you can search for information on Google.
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