javascript - 限制用户选中的复选框数量

Question

我正在尝试开发一个页面，其中有很多复选框，但用户只能选中 2 个复选框。我得到了这段代码，但它不起作用，因为我将其命名为数组。请建议如何在调用 javascript 函数时使用此名称作为复选框。

function checkboxlimit(checkgroup, limit){
    var checkgroup=checkgroup;
    var limit=limit;
    for (var i=0; i<checkgroup.length; i++){
        checkgroup[i].onclick=function(){
            var checkedcount=0;
            for (var i=0; i<checkgroup.length; i++)
                checkedcount+=(checkgroup[i].checked)? 1 : 0;
            if (checkedcount>limit){
                alert("You can only select a maximum of "+limit+" checkboxes");
                this.checked=false;
            }
        }
    }
}
checkboxlimit(document.forms.world.seatdata, 2);

<form id="world" name="world">
<table>
<tr>
<td>
  <input type='checkbox' name='seatdata[]' value='0|12' id="A11" />
  <label for="A11">A11</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|11' id="A10"  />
  <label for="A10">A10</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|10' id="A9"  />
  <label for="A9">A9</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|9' id="A8"  />
  <label for="A8">A8</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|6' id="A7"  />
  <label for="A7">A7</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|5' id="A6"  />
  <label for="A6">A6</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|4' id="A5"  />
  <label for="A5">A5</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|3' id="A4"  />
  <label for="A4">A4</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|2' id="A3" />
  <label for="A3">A3</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|1' id="A2" />
  <label for="A2">A2</label>
</td>
<td>
  <input type='checkbox' name='seatdata[]' value='0|0' id="A1" unchecked />
  <label for="A1">A1</label>
</td>
</tr>
</table>
</form>

Answer 1

只需更改此行

checkboxlimit(document.forms.world.seatdata, 2); 到 checkboxlimit(document.forms.world["seatdata[]"], 2);

或使用document.getElementsByName

checkboxlimit(document.getElementsByName("seatdata[]"), 2);