topic description

limit the number of check boxes and write them out separately in a single method. When you enter a number in the text box to select an element of the check box, there is no response to the limit.

sources of topics and their own ideas

Source: a topic of JavaScript + my own thoughts.
idea: first judge whether the multi-check box is selected. If it has started to select, call the method to limit the number of multi-check box selected. It is said on the Internet that you want to set the click-to-multi-box trigger method, and then set checked to false, in this method, but the text box control multi-box does not need to click on the multi-box. All cannot trigger the method. After the multi-box checked=false is set with the onclick method, the multi-box element is still selected. I checked a lot of information, but it hasn"t been solved.

related codes

< body >

 <form>
      :<br>
      <input type="checkbox" name="hobby" id="hobby1">  
      <input type="checkbox" name="hobby" id="hobby2">  
      <input type="checkbox" name="hobby" id="hobby3">  
      <input type="checkbox" name="hobby" id="hobby4">  
      <input type="checkbox" name="hobby" id="hobby5">  
      <input type="checkbox" name="hobby" id="hobby6">   <br>
      <input type="button" value = "" onclick = "checkall();">
      <input type="button" value = "" onclick = "clearall();">
      
1-6:
      <input id="wb" name="wb" type="text" >
      <input name="ok" type="button" value="" onclick = "checkone();">
    </form>
    <script type="text/javascript">
    function checkall(){
        //
        var hobby = document.getElementsByTagName("input");
          for(var i=0;i<hobby.length;iPP){
          if(hobby[i].type=="checkbox"){      
           hobby[i].checked=true;
            }
          }
    }
    
    function clearall(){
        // 
        var hobby = document.getElementsByName("hobby");
        for(var i=0;i<hobby.length;iPP){
        if(hobby[i].checked==true){
            hobby[i].checked=false;
        }
      }    
        
    }
    
    function checkone(){
        //
        var num=0;
        var j=document.getElementById("wb").value;
        var hobby=document.getElementsByName("hobby");
        if(j<=0||j>6){
            alert("");
        }else
        {
        hobby[j-1].checked=true;
        }
        for(var i=0;i<hobby.length;iPP){
         if(hobby[i].checked==true){
            autoCheck("hobby",3);
         }
       }    
    }
    //  
    function autoCheck(name,limit){
        var hobby=document.getElementsByName(name);
        function check()
        {
          var num=0;
          for(var i=0;i<hobby.length;iPP)
          {
             if(hobby[i].checked){numPP}
             if(num>limit)
             {
                return false;
             }
          }
          return true;
        }
        function checkedNum(){
           for(var i=0;i<hobby.length;iPP){
            if(!check()){
                alert(""+limit+"!");
                hobby[i].checked=false;
                }
            }
        }
     }
    
    </script>
</body>

what result do you expect? What is the error message actually seen?

expectation: whether you click the checkbox or enter the numeric control checkbox in the text box, you can no longer select it when the constraint is reached.
error: the text box input numeric control marquee cannot trigger the method of restricting the marquee, which is not consistent with the method of triggering when the marquee is clicked.