JS 遍历子节点查找元素

 function nextChildNode(node,clazz,tagName){            var count= node.childElementCount;            for(var i=0;i<count;i++){                if(node==undefined || node.children[i]==undefined){                    continue;                }                if(clazz){                    if(node.children[i].getAttribute('class')==clazz){                        return node.children[i];                    }                }else{                    if(node.children[i].tagName==tagName){                        return node.children[i];                    }                }            }            return null;        }                function getChildNode(node,classArg,tagNodeArg){            for(var i=0;i<classArg.length;i++){                node=nextChildNode(node,classArg[i]);            }            for(var i=0;i<tagNodeArg.length;i++){                node=nextChildNode(node,null,tagNodeArg[i]);            }            return node;        }                function getItemId(node){            var classNode=['itemInfo','itemDesc'],tagNode=['P','BUTTON'];            node=getChildNode(node,classNode,tagNode);            alert(node.getAttribute('itemid'));        }                #调用函数        getItemId($(".shopItem")[0]);