<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>使用JQ完成表格隔行换色</title> <script src="https://www.jb51.net/js/jquery.min.js"></script> <script> $(function() { $("tbody tr:odd").css("background-color","aquamarine"); $("tbody tr:even").css("background-color","bisque"); var tb = $("tbody tr"); var oldColor; for(var i=0;i<tb.length;i++) { //alert(oldColor); $("tbody tr")[i].onmouseover = function() { oldColor = this.style.backgroundColor; this.style.backgroundColor = "yellow"; } $("tbody tr")[i].onmouseout = function() { this.style.backgroundColor = oldColor; } } }); </script> </head> <body> <table border-collapse="collapse" cellspacing="0" cellpadding="5"> <thead> <tr> <th>编号</th><th>姓名</th><th>年龄</th> </tr> </thead> <tbody> <tr> <td>1</td><td>张三</td><td>12</td> </tr> <tr> <td>2</td><td>李四</td><td>22</td> </tr> <tr> <td>3</td><td>王五</td><td>13</td> </tr> <tr> <td>4</td><td>马六</td><td>14</td> </tr> <tr> <td>5</td><td>伍六七</td><td>17</td> </tr> <tr> <td>6</td><td>梅花十三</td><td>17</td> </tr> </tbody> </table> </body> </html>
疑问：为什么this.style.backgroundColor = oldColor中的this不能用$("tbody tr")[i]代替？？