function dateGetter(name, size, offset, trim) { return function(date) { var value = date["get" + name]() if (offset > 0 || value > -offset) value += offset if (value === 0 && offset === -12) { // hh h的狀況 value = 12 } return padNumber(value, size, trim) } } var DATE_FORMATS = { yyyy: dateGetter("FullYear", 4), yy: dateGetter("FullYear", 2, 0, true), y: dateGetter("FullYear", 1), MM: dateGetter("Month", 2, 1), M: dateGetter("Month", 1, 1), dd: dateGetter("Date", 2), d: dateGetter("Date", 1), HH: dateGetter("Hours", 2), H: dateGetter("Hours", 1), hh: dateGetter("Hours", 2, -12), h: dateGetter("Hours", 1, -12), mm: dateGetter("Minutes", 2), m: dateGetter("Minutes", 1), ss: dateGetter("Seconds", 2), s: dateGetter("Seconds", 1), sss: dateGetter("Milliseconds", 3) } console.log(DATE_FORMATS.HH(new Date()))