老外写的一个javascript下Date格式化函数

来源：http://blog.youkuaiyun.com/akunshenjk/archive/2008/06/12/2539638.aspx 

老外写的一个javascript下Date格式化函数

Date.prototype.format = function(mask) {
    var d = this;
    var zeroize = function (value, length) {
        if (!length) length = 2;
        value = String(value);
        for (var i = 0, zeros = ''; i < (length - value.length); i++) {
            zeros += '0';
        }
        return zeros + value;
    };   

return mask.replace(/"[^"]*"|'[^']*'|/b(?:d{1,4}|m{1,4}|yy(?:yy)?|([hHMstT])/1?|[lLZ])/b/g, function($0) {
        switch($0) {
            case 'd':    return d.getDate();
            case 'dd':    return zeroize(d.getDate());
            case 'ddd':    return ['Sun','Mon','Tue','Wed','Thr','Fri','Sat'][d.getDay()];
            case 'dddd':    return ['Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday'][d.getDay()];
            case 'M':    return d.getMonth() + 1;
            case 'MM':    return zeroize(d.getMonth() + 1);
            case 'MMM':    return ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'][d.getMonth()];
            case 'MMMM':    return ['January','February','March','April','May','June','July','August','September','October','November','December'][d.getMonth()];
            case 'yy':    return String(d.getFullYear()).substr(2);
            case 'yyyy':    return d.getFullYear();
            case 'h':    return d.getHours() % 12 || 12;
            case 'hh':    return zeroize(d.getHours() % 12 || 12);
            case 'H':    return d.getHours();
            case 'HH':    return zeroize(d.getHours());
            case 'm':    return d.getMinutes();
            case 'mm':    return zeroize(d.getMinutes());
            case 's':    return d.getSeconds();
            case 'ss':    return zeroize(d.getSeconds());
            case 'l':    return zeroize(d.getMilliseconds(), 3);
            case 'L':    var m = d.getMilliseconds();
                    if (m > 99) m = Math.round(m / 10);
                    return zeroize(m);
            case 'tt':    return d.getHours() < 12 ? 'am' : 'pm';
            case 'TT':    return d.getHours() < 12 ? 'AM' : 'PM';
            case 'Z':    return d.toUTCString().match(/[A-Z]+$/);
            // Return quoted strings with the surrounding quotes removed
            default:    return $0.substr(1, $0.length - 2);
        }
    });
};

使用时，先把上面的函数放到javascript声明中，然后，再去条用它，以下是一个调用举例：

var testDate = new Date();

var testStr = testDate.format("yyyy年MM月dd日hh小时mm分ss秒");

alert(testStr);

testStr = testDate.format("yyyy-MM-dd hh:mm");

alert(testStr);