用javascript如何实现全选和全不选

来源：互联网发布：文档管理系统源码编辑：程序博客网时间：2024/05/17 17:16

<!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");

           for(var i=0;i<hobby.length;i++){
                 if(hobby[i].type=="checkbox")
                 {
                     hobby[i].checked=true;
                 }
             }

          // 任务1

        }
        function clearall(){
            var hobby = document.getElementsByName("hobby");
            for(var i=0;i<hobby.length;i++){
                if(hobby[i].type=="checkbox"){
                    hobby[i].checked=false;
                }
            }


        }

        function checkone(){
            var j=document.getElementById("wb").value-1;
            var hobby = document.getElementsByName("hobby");
             for(var i=0;i<hobby.length;i++){
                 if(i==j){
                     hobby[i].checked=true;
                 }

             }
         // 任务3

        }

        </script>
    </body>
</html>

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