How to split the string with comma separated in sql server 2016

Use below function to split the comma separated string value in sql server.
to test use commented sql query

--select SplittedData from SplitStrings('test1.txt,test2.txt',',')
CREATE FUNCTION SplitStrings
(
@SplitData nvarchar(max),
@SplitCharacter nvarchar(5)
)
RETURNS @ReturnValue table
(
UniqueId int identity(1,1),
SplittedData nvarchar(100)
)
AS
BEGIN
Declare @Count int
Set @Count = 1

While (Charindex(@SplitCharacter,@SplitData)>0)
Begin
Insert Into @ReturnValue(SplittedData)
Select
SplittedData = ltrim(rtrim(Substring(@SplitData,1,Charindex(@SplitCharacter,@SplitData)-1)))

Set @SplitData = Substring(@SplitData,Charindex(@SplitCharacter,@SplitData)+1,len(@SplitData))
Set @Count = @Count + 1
End

Insert Into @ReturnValue (SplittedData)
Select SplittedData = ltrim(rtrim(@SplitData))

Return
END