JavaScript/Timing-Functions/GetMonthDays.js at master · sibalonecoding-code/JavaScript · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
/**
  function that takes month number and its year and returns the number of days within it
  * @param monthNumber.
  * @param year.
  e.g.: mahfoudh.arous@gmail.com -> true
  e.g.: mahfoudh.arous.com ->false
*/

import { isLeapYear } from '../Maths/LeapYear'

const getMonthDays = (monthNumber, year) => {
  const the31DaysMonths = [1, 3, 5, 7, 8, 10, 12]
  const the30DaysMonths = [4, 6, 9, 11]

  if (
    !the31DaysMonths.includes(monthNumber) &&
    !the30DaysMonths.includes(monthNumber) &&
    monthNumber !== 2
  ) {
    throw new TypeError('Invalid Month Number.')
  }

  if (the31DaysMonths.includes(monthNumber)) {
    return 31
  }

  if (the30DaysMonths.includes(monthNumber)) {
    return 30
  }

  if (isLeapYear(year)) {
    return 29
  }

  return 28
}

export { getMonthDays }