jQuery年月日（年龄）选择插件

下载地址：https://www.helloweba.net/javascript/263.html

<!DOCTYPE HTML>
<html>

    <head>
        <meta charset="utf-8">
        <title>jQuery年月日（生日）选择器</title>
        <style>

        </style>
        <script type="text/javascript" src="jquery.js"></script>
    </head>

    <body>
        <div class="demo">
            <p>
                默认值：<br/>
                <label>生日：</label>
                <select class="sel_year" rel="2000"></select>年
                <select class="sel_month" rel="2"></select>月
                <select class="sel_day" rel="14"></select>日
            </p>
        </div>
        <script type="text/javascript" src="birthday.js"></script>
        <script>
            $(function() {
                $.ms_DatePicker({
                    YearSelector: ".sel_year",
                    MonthSelector: ".sel_month",
                    DaySelector: ".sel_day"
                });
                $.ms_DatePicker();
            });
        </script>
    </body>

</html>

birthday.js内容：(来自github)

(function($){
$.extend({
ms_DatePicker: function (options) {
            var defaults = {
                YearSelector: "#sel_year",
                MonthSelector: "#sel_month",
                DaySelector: "#sel_day",
                FirstText: "--",
                FirstValue: 0
            };
            var opts = $.extend({}, defaults, options);
            var $YearSelector = $(opts.YearSelector);
            var $MonthSelector = $(opts.MonthSelector);
            var $DaySelector = $(opts.DaySelector);
            var FirstText = opts.FirstText;
            var FirstValue = opts.FirstValue;

            // 初始化
            var str = "<option value="" + FirstValue + "">" + FirstText + "</option>";
            $YearSelector.html(str);
            $MonthSelector.html(str);
            $DaySelector.html(str);

            // 年份列表
            var yearNow = new Date().getFullYear();
            var yearSel = $YearSelector.attr("rel");
            for (var i = yearNow; i >= 1900; i--) {
                var sed = yearSel==i?"selected":"";
                var yearStr = "<option value="" + i + "" " + sed+">" + i + "</option>";
                $YearSelector.append(yearStr);
            }

            // 月份列表
            var monthSel = $MonthSelector.attr("rel");
            for (var i = 1; i <= 12; i++) {
                var sed = monthSel==i?"selected":"";
                var monthStr = "<option value="" + i + "" "+sed+">" + i + "</option>";
                $MonthSelector.append(monthStr);
            }

            // 日列表(仅当选择了年月)
            function BuildDay() {
                if ($YearSelector.val() == 0 || $MonthSelector.val() == 0) {
                    // 未选择年份或者月份
                    $DaySelector.html(str);
                } else {
                    $DaySelector.html(str);
                    var year = parseInt($YearSelector.val());
                    var month = parseInt($MonthSelector.val());
                    var dayCount = 0;
                    switch (month) {
                        case 1:
                        case 3:
                        case 5:
                        case 7:
                        case 8:
                        case 10:
                        case 12:
                            dayCount = 31;
                            break;
                        case 4:
                        case 6:
                        case 9:
                        case 11:
                            dayCount = 30;
                            break;
                        case 2:
                            dayCount = 28;
                            if ((year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0)) {
                                dayCount = 29;
                            }
                            break;
                        default:
                            break;
                    }
                    
                    var daySel = $DaySelector.attr("rel");
                    for (var i = 1; i <= dayCount; i++) {
                        var sed = daySel==i?"selected":"";
                        var dayStr = "<option value="" + i + "" "+sed+">" + i + "</option>";
                        $DaySelector.append(dayStr);
                    }
                }
            }
            $MonthSelector.change(function () {
                BuildDay();
            });
            $YearSelector.change(function () {
                BuildDay();
            });
            if($DaySelector.attr("rel")!=""){
                BuildDay();
            }
        } // End ms_DatePicker
});
})(jQuery);

怎么得到选择的值？

function getBirthday() {
                var date = "";
                date += $(".sel_year").val();
                date += "-";
                if (parseInt($(".sel_month").val()) < 10) {
                    date += "0";
                    date += $(".sel_month").val();
                } else {
                    date += $(".sel_month").val();
                }
                date += "-";
                if (parseInt($(".sel_day").val()) < 10) {
                    date += "0";
                    date += $(".sel_day").val();
                } else {
                    date += $(".sel_day").val();
                }
                return date;
            }

原文作者：祈澈姑娘技术博客：https://www.jianshu.com/u/05f416aefbe1