js--判断年月日的一些简单例子

<script language="javascript" type="text/javascript">
       var d = new Date();
       alert(d.getDate());
    </script>

判断年月日是不是符合规范。2月31就不对

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

        var year = prompt("nian", "") * 1, yue = prompt("yue", "") * 1, ri = prompt("ri", "") * 1;
        var d = new Date();
        d.setFullYear(year);
        d.setMonth(yue - 1);
        d.setDate(ri);
        if (d.getFullYear() == year && d.getMonth() + 1 == yue && d.getDate() == ri) {
            alert("yes");
        } else {
            alert("no");
        }
    
    </script>

给一个日期，输出是星期几

<script language="javascript" type="text/javascript">
        var year = prompt("nian", "") * 1, yue = prompt("yue", "") * 1, ri = prompt("ri", "") * 1;
        var d = new Date();
        d.setFullYear(year);
        d.setMonth(yue - 1);
        d.setDate(ri);
        alert(d.getDay());
    
    </script>