js Date扩展Format()函数

Date.prototype.Format = function (formatStr) {
            var str = formatStr;
            var Week = ['日', '一', '二', '三', '四', '五', '六'];

            str = str.replace(/yyyy|YYYY/, this.getFullYear());
            str = str.replace(/yy|YY/, (this.getYear() % 100) > 9 ? (this.getYear() % 100).toString() : '0' + (this.getYear() % 100));

            str = str.replace(/MM/, this.getMonth() > 9 ? (this.getMonth() + 1).toString() : '0' + (this.getMonth() + 1));
            str = str.replace(/M/g, this.getMonth());

            str = str.replace(/w|W/g, Week[this.getDay()]);

            str = str.replace(/dd|DD/, this.getDate() > 9 ? this.getDate().toString() : '0' + this.getDate());
            str = str.replace(/d|D/g, this.getDate());

            str = str.replace(/hh|HH/, this.getHours() > 9 ? this.getHours().toString() : '0' + this.getHours());
            str = str.replace(/h|H/g, this.getHours());
            str = str.replace(/mm/, this.getMinutes() > 9 ? this.getMinutes().toString() : '0' + this.getMinutes());
            str = str.replace(/m/g, this.getMinutes());

            str = str.replace(/ss|SS/, this.getSeconds() > 9 ? this.getSeconds().toString() : '0' + this.getSeconds());
            str = str.replace(/s|S/g, this.getSeconds());

            return str;
        }