檢查form表單的radio元素是否被選中

<input type="radio" id="gender" name="gender" value="male">male
<input type="radio" id="gender" name="gender" value="female">female

function check(){ var ifCheck=document.getElementsByName('gender')[0].checked ||document.getElementsByName('gender')[1].checked?true:false; if(!ifCheck){ alert("您沒有選擇性別。"); } } code