用的函数是setFullYear（），getFullYear（）
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="../common/jquery-1.8.3.min.js"></script>
</head>
<body>
<div>
<label for="">出生年</label>
<input type="text" id="year">
</div>
<div>
<label for="">出生月</label>
<input type="text" id="month">
</div>
<div>
<label for="">出生日</label>
<input type="text" id="date">
</div>
<div>
<button id="btn">提交</button>
</div>
</body>
<script>
$("#btn").click(function(){
var year = $("#year").val();
var month = $("#month").val();
var date = $("#date").val();
if(year == '' && month == '' && date == ''){
alert("请输入相应的出生年月日");
return;
}
var myDate = new Date();
myDate.setFullYear(year ,month-1 , date);
var nowDate = new Date();
console.log(nowDate.getFullYear()-18);
nowDate.setFullYear(nowDate.getFullYear()-18);
if((nowDate - myDate) < 0 ){
alert("年龄不满18岁");
}
alert("提交成功");
return true;
})
</script>
</html>