js中格式化时间字符串

<script>
function formatDate(date, format) {
if (!date) return;
if (!format) format = "yyyy-MM-dd";
switch(typeof date) {
case "string":
date = new Date(date.replace(/-/, "/"));
break;
case "number":
date = new Date(date);
break;
}
if (!date instanceof Date) return;
var dict = {
"yyyy": date.getFullYear(),
"M": date.getMonth() + 1,
"d": date.getDate(),
"H": date.getHours(),
"m": date.getMinutes(),
"s": date.getSeconds(),
"MM": ("" + (date.getMonth() + 101)).substr(1),
"dd": ("" + (date.getDate() + 100)).substr(1),
"HH": ("" + (date.getHours() + 100)).substr(1),
"mm": ("" + (date.getMinutes() + 100)).substr(1),
"ss": ("" + (date.getSeconds() + 100)).substr(1)
};
return format.replace(/(yyyy|MM?|dd?|HH?|ss?|mm?)/g, function() {
return dict[arguments[0]];
});
}

alert(formatDate("2010-04-30", "yyyy-MM-dd HH:mm:ss"));
alert(formatDate("2010-4-29 1:50:00", "yyyy-MM-dd HH:mm:ss"));
</script>