javascript - 我如何更改此 Javascript 代码来验证数据

Question

我需要添加什么才能根据已选择的复选框数量进行验证？我希望用户在提交数据之前至少选择两个复选框。这是我的 JavaScript 代码:

<script type="text/javascript" language="JavaScript">

function checkCheckBoxes(theForm) {
    if (
    theForm.Conservatives.checked == false &&
    theForm.Labour.checked == false &&
    theForm.LiberalDemocrats.checked == false) 
    {
        alert ('Choose At Least Two Parties Who Will Be Standing For This Election');
        return false;
    } else {    
        return true;
    }
}

</script> 

当前的 Javascript 代码仅验证是否选中了任何复选框，但我希望它验证两个复选框。

Answer 1

数一下检查了多少个，看看是否小于 2。

function checkCheckBoxes(theForm) {
    var cnt = 0;
    if (theForm.Conservatives.checked) ++cnt;
    if (theForm.Labour.checked) ++cnt;
    if (theForm.LiberalDemocrats.checked) ++cnt;
    if (cnt < 2) {
        alert ('Choose At Least Two Parties Who Will Be Standing For This Election');
        return false;
    } else {    
        return true;
    }
}