Convert a string pair to a dictionary (temporary table) User-Defined Function (SQL)

This function is often used, so it is written as a user-defined function. I believe it is practical.
Convert a pair of strings into a dictionary (temporary table)
However, when raiserror is used in a custom function to throw an error (stored in a stored procedure), I hope you can give me some advice.
Usage:
Select * From f_dic ('aa, bfeab, CC, DXD, eeeee ', '1, 2, 4, 1, 5 ')
Result
Aa 1
Bfeab 2
CC 4
DXD 1
Eeeee 5 create function [DBO]. [f_dic]
(
@ Keys varchar (8000 ),
@ Values varchar (8000)
)
Returns @ t table ([Key] varchar (20), value varchar (20 ))
As
Begin
-- If Len (@ keys)-len (replace (@ keys, ',') <> Len (@ values)-len (replace (@ values ,', ',''))
-- Begin
-- Raiserror (n' parameter @ keys length is different from that of @ values ',
-- 10, 1 );
-- End
While (charindex (',', @ keys) <> 0)
Begin
Insert @ T ([Key], value) values (substring (@ keys, 1, charindex (',', @ keys)-1), substring (@ values, 1, charindex (',', @ values)-1 ))
Set @ keys = stuff (@ keys, 1, charindex (',', @ keys ),'')
Set @ values = stuff (@ values, 1, charindex (',', @ values ),'')
End
Insert @ T ([Key], value) values (@ keys, @ values)
Return
End