1507. Reformat Date.js

// Given a date string in the form Day Month Year, where:

// Day is in the set {"1st", "2nd", "3rd", "4th", ..., "30th", "31st"}.
// Month is in the set {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}.
// Year is in the range [1900, 2100].
// Convert the date string to the format YYYY-MM-DD, where:

// YYYY denotes the 4 digit year.
// MM denotes the 2 digit month.
// DD denotes the 2 digit day.

// Example 1:

// Input: date = "20th Oct 2052"
// Output: "2052-10-20"
// Example 2:

// Input: date = "6th Jun 1933"
// Output: "1933-06-06"
// Example 3:

// Input: date = "26th May 1960"
// Output: "1960-05-26"

// Constraints:

// The given dates are guaranteed to be valid, so no error handling is necessary.

const reformatDate = date => {
	let months = [
		'Jan',
		'Feb',
		'Mar',
		'Apr',
		'May',
		'Jun',
		'Jul',
		'Aug',
		'Sep',
		'Oct',
		'Nov',
		'Dec',
	]
	let [day, month, year] = date.split(' ')
	return (
		year +
		'-' +
		('00' + (months.indexOf(month) + 1)).substr(-2) +
		'-' +
		('0' + parseInt(day)).substr(-2)
	)
}