第一、el.setAttribute(‘class’,‘abc’)
<!DOCTYPE HTML>
<HTML>
<HEAD>
<meta charset="utf-8" />
<title>setAttribute('class', 'abc')</title>
<style type="text/css">
.abc {
background: red;
}
</style>
</HEAD>
<BODY>
<div id="div">test div</div>
<script>
var div = document.getElementById('div');
div.setAttribute("class", "abc");
</script>
</BODY>
</HTML>
第二、 el.setAttribute(‘className’, ‘abc’)
<!DOCTYPE HTML>
<HTML>
<HEAD>
<meta charset="utf-8" />
<title>setAttribute('className', 'abc')</title>
<style type="text/css">
.abc {
background: red;
}
</style>
</HEAD>
<BODY>
<div id="div">test div</div>
<script>
var div = document.getElementById('div');
div.setAttribute("className", "abc");
</script>
</BODY>
</HTML>
第三、el.className = ‘abc’
<!DOCTYPE HTML>
<HTML>
<HEAD>
<meta charset="utf-8" />
<title>el.className = 'abc'</title>
<style type="text/css">
.abc {
background: red;
}
</style>
</HEAD>
<BODY>
<div id="div">test div</div>
<script>
var div = document.getElementById('div');
div.className = 'abc';
</script>
</BODY>
</HTML>