PowerShell use regular expression to split a string

Question

This is my code:

[regex]::split("1,2   3", '(,|\s)+')

What I want is an array with three elements 1, 2, 3, however, what I got it is an array with five elements.

PS C:\Users\a> [regex]::split("1,2   3", '(,|\s)+').Length
5
PS C:\Users\a>

How to get what I want?

Update

Add the actual split result instead of the length.

PS E:\> [regex]::split("1,2   3", '(,|\s)+')
1
,
2

3
PS E:\> [regex]::split("1,2   3", '(,|\s)+').length
5
PS E:\> [regex]::split("1,2   3", '[,\s]+')
1
2
3
PS E:\> [regex]::split("1,2   3", '[,\s]+').length
3
PS E:\>

Update

Thanks @Matt's answer and it points me to the right direction. From help about_split the doc states that:

By default, the delimiter is omitted from the results. To preserve all or part of the delimiter, enclose in parentheses the part that you want to preserve.

Below are some of my testing.

PS E:\tutorial>     "Lastname/:/FirstName/:/Address" -split "/(:)/"
Lastname
:
FirstName
:
Address
PS E:\tutorial>     "Lastname/:/FirstName/:/Address" -split "/:/"
Lastname
FirstName
Address
PS E:\tutorial>     "Lastname/:/FirstName/:/Address" -split "(/:/)"
Lastname
/:/
FirstName
/:/
Address
PS E:\tutorial>     "Lastname/:/FirstName/:/Address" -split "/:(/)"
Lastname
/
FirstName
/
Address
PS E:\tutorial>     "Lastname/:/FirstName/:/Address" -split "(/):(/)"
Lastname
/
/
FirstName
/
/
Address
PS E:\tutorial>     "Lastname/:/FirstName/:/Address" -split "(/)(:)(/)"
Lastname
/
:
/
FirstName
/
:
/
Address
PS E:\tutorial> [regex]::split("Lastname/:/FirstName/:/Address", '/(:)/')
Lastname
:
FirstName
:
Address
PS E:\tutorial> [regex]::split("Lastname/:/FirstName/:/Address", '/:/')
Lastname
FirstName
Address
PS E:\tutorial> [regex]::split("Lastname/:/FirstName/:/Address", '/:(/)')
Lastname
/
FirstName
/
Address
PS E:\tutorial> [regex]::split("Lastname/:/FirstName/:/Address", '(/):(/)')
Lastname
/
/
FirstName
/
/
Address
PS E:\tutorial> [regex]::split("Lastname/:/FirstName/:/Address", '(/)(:)(/)')
Lastname
/
:
/
FirstName
/
:
/
Address
PS E:\tutorial>

Answer 1

I might be late to the party but below example works for me.

"Lastname,FirstName, Address pincode" -split "[\s,]+"
Lastname
FirstName
Address
pincode