javascript兼容性问题总结与记录

 function getElementsByClass(_className,elemParent){
        var elemParent = elemParent||document;//elemParent为父元素
       if(elemParent.getElementsByClassName){
           return elemParent.getElementsByClassName(_className);
        }else{
            var elems = elemParent.getElementsByTagName(‘*‘); 
            var arr = [];
            for(var i=0;i<elems.length;i++){
                if(elems[i].nodeType==1){//可以去掉
                    var classnames = elems[i].className.split(/\s+/);
                    for(var j=0;j<classnames.length;j++){
                        if(classnames[j]==_className){
                            arr.push(elems[i]);
                            break;
                        }
                    }
                }
            }
            return arr;
        }
    }