javascript - checkbox condition

Question

<input id="a1" type="checkbox">
<label for="a1">1</label>
<input id="a2" type="checkbox">
<label for="a2">2</label>
<input id="a3" type="checkbox">
<label for="a3">3</label>
<input id="a4" type="checkbox">
<label for="a4">4</label>
<input id="a5" type="checkbox">
<label for="a5">5</label>

<script>
$(function()
{
  disabledOtherBox();
  $("#a1").click(disabledOtherBox);
  disabledA1Box();
  $("#a2,#a3,#a4,#5").click(disabledA1Box);
});

function disabledOtherBox()
{
  if (this.checked)
  {
    $("#a2,#a3,#a4,#a5").attr("disabled", true);
  }
  else
  {
    $("#a2,#a3,#a4,#a5").removeAttr("disabled");
  }
}

function disabledA1Box()
{
  if (this.checked)
  {
    $("#a1").attr("disabled", true);
  }
  else
  {
    $("#a1").removeAttr("disabled");
  }
}
</script>

The above are the conditions I wrote
If a1 is checked
a2~5 is locked

If one of a2~a5 is checked
, then a1 is locked

I want to add another condition but I still can’t figure it out
That is, assuming that one of a2~5 is checked (or two, three, or four are all checked)
Then a1 Just lock it
Unless a2~5 are not checked
, a1 will be opened

Answer 1

<script>
    $(function(){
        var a1 = $("#a1");
        var other = $("#a2,#a3,#a4,#a5");
        
        a1.click(function(){
            disabledBox(other,this.checked)
        });
        
        other.click(function() {
              var r = false;
            
            other.each(function() {
                if(this.checked) {
                    r = true;
                    return false;
                  }
            })
              
              disabledBox(a1,r)
        });
       
        //如a1已勾选，则#a2,#a3,#a4,#5锁住
        //disabledBox(other,a1.attr('checked'))
        
        //如#a2,#a3,#a4,#5其中一个或多个已勾选，则a1锁住
        other.each(function() {
             if(this.checked) {
                disabledBox(a1,true)
                 return false;
             }
        })
    });
    
    function disabledBox(el,disabled){
        el.attr("disabled", !!disabled);
    }
</script>