Solution To Reddit Daily Programmer #245 Easy - Date Dilemma

date-dilemma.ps1

#https://www.reddit.com/r/dailyprogrammer/comments/3wshp7/20151214_challenge_245_easy_date_dilemma/
#Solution to Reddit Daily Programmer 245 Easy.

#Function to parse from the user's specified format into a standard one.
#Void, dumps to STDOUT.
function ParseDate
{
	param (
		$UserFormat
	)
	
	#Make an array to hold the values.
	$splitValues = @()
	
	#Check how the items are separated and split accordingly.
	if($UserFormat.Contains(" ")) {
		$splitValues = $UserFormat.Split(" ")
	} elseif($UserFormat.Contains("-")) {
		$splitValues = $UserFormat.Split("-")
	} elseif($UserFormat.Contains("/")) {
		$splitValues = $UserFormat.Split("/")
	}
	
	#Figure out what each part is and concatenate them together.
	if($splitValues.Count -gt 0) {
		if($splitValues[0].Length -gt 2) {
			#We know this is Y M D.
			$year = $splitValues[0]
			$month = $splitValues[1]
			$day = $splitValues[2]
		} else {
			#If year isn't first, it's M D Y.
			$month = $splitValues[0]
			$day = $splitValues[1]
			$year = $splitValues[2]
		}
		
		#Make sure month and day are both two digits.
		if($month.Length -lt 2) {
			$month = "0$month"
		}
		if($day.Length -lt 2) {
			$day = "0$day"
		}
		
		#Make sure the year is 4 digits. Assume anything with two digits is in 20xx.
		if($year.Length -lt 4) {
			$year = "20$year"
		}
		
		#Write it all out.
		Write-Output "$year-$month-$day"
	} else {
		#Print an error if the array is empty for some reason because the splits failed.
		Write-Output "Error! Could not parse fields for: $UserFormat"
	}
}

#Main code.
#Initialize the input array.
$inputArray = "2/13/15", "1-31-10", "5 10 2015", "2012 3 17", "2001-01-01", "2008/01/07"

#Loop through each item, passing to the function to parse them.
foreach($item in $inputArray) {
	ParseDate -UserFormat $item
}