js实现addClass,removeClass,hasClass

源地址: [url]http://snipplr.com/view/3561/addclass-removeclass-hasclass/[/url]

function hasClass(ele,cls) {
   return ele.className.match( new RegExp('(\\s|^)'+cls+'(\\s|$)'));
}

function addClass(ele,cls) {
   if (! this.hasClass(ele,cls)) ele.className += " "+cls;
}

function removeClass(ele,cls) {
   if (hasClass(ele,cls)) {
          var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
    ele.className=ele.className.replace(reg,' ');
  }
}

//call the functions
addClass(document.getElementById( "test"), "test");
removeClass(document.getElementById( "test"), "test")
if(hasClass(document.getElementById( "test"), "test")){ //do something};