Baidu-web today to see the front-end development Engineer-Pen test questions, found a long-term neglect of their own problems.
Some colleagues used the code I wrote to get the elements, and the results were not taken. Reason, I believe because she wrote "-" in the class name, which in the regular will be treated as a meta character. So the code can be as written on that front end:
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| var tea = (function () {
function Getelementsbyclassname (classname,tag,parent) {
". All" is used in the DHTML www.111cn.net, and when tag equals "*",
If the browser supports ". All", otherwise, use the standard Dom method
var alltags= (Tag = = "*" && parent.all)? Parent.all:parent.getElementsByTagName (tag);
var matchingelements= new Array ();
Because '-' is the meta character in the regular expression, and the ClassName '-' is legal,
So, before you write className to a regular expression, you first escape the '-'
Classname=classname.replace (/-/g, "\-");
var regex=new RegExp ("(^|\b)" +classname+ "(\b|$)");
var element;
for (Var i=0;i<alltags.length;i++) {
Element=alltags[i];
if (Regex.test (Element.classname)) {
Matchingelements.push (Element);
}
}
return matchingelements;
}
return {
Getelementsbyclassname:getelementsbyclassname
};
})(); |
Group of 99 Brothers, told younger brother said, now generally not popular such a matching way, you can use the following ways:
| The code is as follows |
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(' +classname.tolowercase () + '). IndexOf (' + class+ to be judged ')!==-1
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Example 2
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|
<script type= "Text/javascript" >
Window.onload = function ()
{var topmenus = getclass (' li ', ' Topmenu ');
for (Var i=0;i < topmenus.length; i++)
{
alert (topmenus[i].innerhtml);
}
}
function GetClass (tagname,classname)//Get the element with label name TagName, class name ClassName
{
if (document.getelementsbyclassname)//support for this function
{return document.getelementsbyclassname (className);
}
Else
{var tags=document.getelementsbytagname (tagName);//Get Label
The Var tagarr=[];//is used to return the element with the class name classname
for (Var i=0;i < tags.length; i++)
{
if (Tags[i].class = = className)
{
Tagarr[tagarr.length] = tags[i];//Save the element that satisfies the condition
}
}
return Tagarr;
}
}
</script>
<body>
<ul id= "NAV" >
<li class= "Topmenu" ><a href= "#" > This is all about the product </a>
<ul class= "submenu" >
<li><a href= "#" > here are all products 1</a></li>
<li><a href= "#" > here are all products 2</a></li>
<li><a href= "#" > here are all products 3</a></li>
<li><a href= "#" > here are all products 4</a></li>
<li><a href= "#" > here are all products 5</a></li>
<li><a href= "#" > here are all products 6</a></li>
</ul>
</li>
<li class= "Topmenu" ><a href= "#" > Service Introduction </a>
<ul class= "submenu" >
<li><a href= "#" > Service 1</a></li>
<li><a href= "#" > Service 2</a></li>
<li><a href= "#" > Service 3</a></li>
<li><a href= "#" > Service 4</a></li>
</ul>
</li>
<li class= "Topmenu" ><a href= "#" > Success Stories </a>
<ul class= "submenu" >
<li><a href= "#" > Case 1</a></li>
<li><a href= "#" > Case 2</a></li>
<li><a href= "#" > Case 3</a></li>
<li><a href= "#" > Case 4</a></li>
</ul>
</li>
<li class= "Topmenu" ><a href= "#" > About we'll find you </a>
<ul class= "submenu" >
<li><a href= "#" > We'll find you 1</a></li>.
<li><a href= "#" > We'll find you 2</a></li>.
<li><a href= "#" > We'll find you 3</a></li>.
<li><a href= "#" > We'll find you 4</a></li>.
</ul>
</li>
<li class= "Topmenu" ><a href= "#" > will contact us. We'll find you. </a>
<ul class= "submenu" >
<li><a href= "#" > here will contact us and we'll find you 1</a></li>
<li><a href= "#" > here will contact us and we'll find you 2</a></li>
<li><a href= "#" > here will contact us and we'll find you 3</a></li>
<li><a href= "#" > here will contact us and we'll find you 4</a></li>
<li><a href= "#" > here will contact us and we'll find you 5</a></li>
<li><a href= "#" > here will contact us and we'll find you 6</a></li>
<li><a href= "#" > here will contact us and we'll find you 7</a></li>
</ul>
</li>
</ul>
</body>
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