<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <style> /*input,li,ul,a{margin: 0; padding: 0;}若是删掉这句话,li的点会出现*/ #ul li{float:left;clear:left;position: relative;width: auto;padding-right: 12px;padding-top: 10px;} #ul i{position: absolute;right: 0;top: 0;color: #f00;cursor: pointer;} </style> </head> <body> <input id="text" type="text" value="" /><br/> <input id="btn" type="button" value="在ul中插入新内容"/> <ul id="ul"> <!--<span>dfhl</span><i></i>--> </ul> </body> <script> var textObj=document.getElementById("text"); var btnObj=document.getElementById("btn"); var ulObj=document.getElementById("ul"); btnObj.onclick= function () {//点击按钮 var val=textObj.value; var spanObj=ulObj.getElementsByTagName("span"); for(var i=0;i<spanObj.length;i++){ if(spanObj[i].innerHTML==val) {alert("输入重复"); return;}//强制跳出函数,并返回一个结果 } var liNode=document.createElement("li"); liNode.innerHTML="<span>"+val+"</span><i>x</i>"; ulObj.appendChild(liNode); textObj.value=""; }; ulObj.onclick=function(e){ var event=e || window.event; var target=event.target || event.srcElement; if(target.nodeName=="I"){//此处应大写 target.parentNode.parentNode.removeChild(target.parentNode);//target是一个对象 } } </script> </html>