Optimize format method

src/index.js

@@ -278,34 +278,63 @@ class Dayjs {
  return isLowercase ? m.toLowerCase() : m
  })
 
- const matches = {
- YY: String(this.$y).slice(-2),
- YYYY: Utils.s(this.$y, 4, '0'),
- M: $M + 1,
- MM: Utils.s($M + 1, 2, '0'),
- MMM: getShort(locale.monthsShort, $M, months, 3),
- MMMM: getShort(months, $M),
- D: this.$D,
- DD: Utils.s(this.$D, 2, '0'),
- d: String(this.$W),
- dd: getShort(locale.weekdaysMin, this.$W, weekdays, 2),
- ddd: getShort(locale.weekdaysShort, this.$W, weekdays, 3),
- dddd: weekdays[this.$W],
- H: String($H),
- HH: Utils.s($H, 2, '0'),
- h: get$H(1),
- hh: get$H(2),
- a: meridiemFunc($H, $m, true),
- A: meridiemFunc($H, $m, false),
- m: String($m),
- mm: Utils.s($m, 2, '0'),
- s: String(this.$s),
- ss: Utils.s(this.$s, 2, '0'),
- SSS: Utils.s(this.$ms, 3, '0'),
- Z: zoneStr // 'ZZ' logic below
+ const matches = (match) => {
+ switch (match) {
+ case 'YY':
+ return String(this.$y).slice(-2)
+ case 'YYYY':
+ return Utils.s(this.$y, 4, '0')
+ case 'M':
+ return $M + 1
+ case 'MM':
+ return Utils.s($M + 1, 2, '0')
+ case 'MMM':
+ return getShort(locale.monthsShort, $M, months, 3)
+ case 'MMMM':
+ return getShort(months, $M)
+ case 'D':
+ return this.$D
+ case 'DD':
+ return Utils.s(this.$D, 2, '0')
+ case 'd':
+ return String(this.$W)
+ case 'dd':
+ return getShort(locale.weekdaysMin, this.$W, weekdays, 2)
+ case 'ddd':
+ return getShort(locale.weekdaysShort, this.$W, weekdays, 3)
+ case 'dddd':
+ return weekdays[this.$W]
+ case 'H':
+ return String($H)
+ case 'HH':
+ return Utils.s($H, 2, '0')
+ case 'h':
+ return get$H(1)
+ case 'hh':
+ return get$H(2)
+ case 'a':
+ return meridiemFunc($H, $m, true)
+ case 'A':
+ return meridiemFunc($H, $m, false)
+ case 'm':
+ return String($m)
+ case 'mm':
+ return Utils.s($m, 2, '0')
+ case 's':
+ return String(this.$s)
+ case 'ss':
+ return Utils.s(this.$s, 2, '0')
+ case 'SSS':
+ return Utils.s(this.$ms, 3, '0')
+ case 'Z':
+ return zoneStr // 'ZZ' logic below
+ default:
+ break
+ }
+ return null
  }
 
- return str.replace(C.REGEX_FORMAT, (match, $1) => $1 || matches[match] || zoneStr.replace(':', '')) // 'ZZ'
+ return str.replace(C.REGEX_FORMAT, (match, $1) => $1 || matches(match) || zoneStr.replace(':', '')) // 'ZZ'
  }
 
  utcOffset() {