<!DOCTYPE HTML><html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>无标题文档</title> </head> <body> <form> 请选择你爱好:<br> <input type="checkbox" name="hobby" id="hobby1"> 音乐 <input type="checkbox" name="hobby" id="hobby2"> 登山 <input type="checkbox" name="hobby" id="hobby3"> 游泳 <input type="checkbox" name="hobby" id="hobby4"> 阅读 <input type="checkbox" name="hobby" id="hobby5"> 打球 <input type="checkbox" name="hobby" id="hobby6"> 跑步 <br> <input type="button" value = "全选" onclick = "checkall();"> <input type="button" value = "全不选" onclick = "clearall();"> <p>请输入您要选择爱好的序号,序号为1-6:</p> <input id="wb" name="wb" type="text" > <input name="ok" type="button" value="确定" onclick = "checkone();"> </form> <script type="text/javascript"> function checkall(){ var hobby = document.getElementsByTagName("input"); // 任务1 for(var i = 0;i<hobby.length;i++){ hobby[i].checked = true; } } function clearall(){ var hobby = document.getElementsByName("hobby"); // 任务2 for(var i = 0;i<hobby.length;i++){ hobby[i].checked = false; } } function checkone(){ var j=document.getElementById("wb").value; // 任务3 var arr=j.split(""); for(var i = 0;i<j.length;i++){ var k=parseInt(arr[i]); hobby[k].checked = true; } } </script> </body></html>