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的情况

            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()))