复制代码 代码如下:

function MyClass () {}

MyClass.hasClassName = function(element, className)

{

if (!element) return;

var elementClassName = element.className;

if (elementClassName.length == 0) return false;

//用正则表达式判断多个class之间是否存在真正的class（前后空格的处理）

if (elementClassName == className || elementClassName.match(new RegExp("(^|s)" + className + "(s|$)")))

return true;

return false;

};

MyClass.addClassName = function(element, className)

{

if (!element) return;

var elementClassName = element.className;

if (elementClassName.length == 0)

{

element.className = elementClassName;

return;

}

if (elementClassName == className || elementClassName.match(new RegExp("(^|s)" + className + "(s|$)")))

return;

element.className = elementClassName + " " + className;

};

MyClass.removeClassName = function(element, className)

{

if (!element) return;

var elementClassName = element.className;

if (elementClassName.length == 0) return;

if(elementClassName == className)

{

element.className = "";

return;

}

if (elementClassName.match(new RegExp("(^|s)" + className + "(s|$)")))

element.className = elementClassName.replace((new RegExp("(^|s)" + className + "(s|$)"))," ");

};