<script>
window.onload = function()
{
var oDiv = document.getElementById('div1');
var oDiv2 = document.getElementById('div2');
addClass(oDiv,'box1');
removeClass(oDiv2,'box');
function addClass(obj,className)
{
//如果原来没有Class
if(obj.className == ''){
obj.className = className;
} else{
//如果原来有class
var arrClassName = obj.className.split(' ');
var _index = arrIndexOf(arrClassName,className);
if(_index == -1)
{
//如果要添加的class在原来的class中不存在
obj.className += ' ' + className;
}
//如果要添加的class在原来的class中存在
}
};
function removeClass(obj,className)
{
//如果原来有class
if(obj.className !='')
{
var arrClassName = obj.className.split(' ');
var _index = arrIndexOf(arrClassName,className);
//如果有我要移除的class
if(_index != -1)
{
arrClassName.splice(_index,1);
obj.className = arrClassName.join(' ');
}
}
//如果原来没有class就什么都不做
};
function arrIndexOf(arr,v)
{
for(var i=0;i<arr.length;i++)
{
if(arr[i] == v)
{
return i;
}
}
return -1;
};
};
</script>
<body>
<div id="div1" class="box">aaaa</div>
<div id="div2" class="box">bbb</div>
</body>