I hope you can help me with a js issue.

A js question. I hope you can help me find a layer called & lt; divclass = & quot; demo & quot; & gt; he wants to use js to set class = & quot; replace demo & quot; with id = & quot; demo & quot; But varstr = & quot; with a js question. please help me.
I have a layer called

He wants to use js to replace class = "demo" with id = "demo"

But var str = "" How can I write it here?

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Find the object, obj. id = 'demo'; obj. className = '';
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You already have an id, right?
?
To change
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The problem is answered! Please

Document. body. innerHTML = document. body. innerHTML. replace (/class = demo/I, 'id = Demo ');
This is a simple way of writing. I will give you some ideas.
For complex and complete solutions, go to web development-javascript layout
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So I am asking him what the problem is. haha
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Jquery
$ ('. Demo'). attr ('id') = 'demo ';
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Discussion

The problem is answered! Please

Document. body. innerHTML = document. body. innerHTML. replace (/class = demo/I, 'id = Demo ');
This is a simple way of writing. I will give you some ideas.
For complex and complete solutions, go to web development-javascript layout