Strange udf function https://feedback.azure.com/forums/908035-sql-server/suggestions/39853927-lee-hotmail-com

TryParseAFID.sql

print @@version
USE tempdb;
GO

SET ANSI_NULLS ON;
GO
SET QUOTED_IDENTIFIER ON;
GO

CREATE OR ALTER FUNCTION dbo.TryParseAFID (@stringAFID nvarchar(MAX))
RETURNS bigint
WITH SCHEMABINDING--,    INLINE = OFF
AS
BEGIN
    DECLARE @AfidParse bigint;

    IF CHARINDEX('%', @stringAFID ) > 0

    BEGIN
        IF CHARINDEX('%20', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%20',' ' );
        IF CHARINDEX('%21', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%21','!' );
        IF CHARINDEX('%23', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%23','#' );
        IF CHARINDEX('%24', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%24','$' );
        IF CHARINDEX('%25', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%25','%' );
        IF CHARINDEX('%26', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%26','&' );
        IF CHARINDEX('%27', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%27','''');
        IF CHARINDEX('%28', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%28','(' );
        IF CHARINDEX('%29', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%29',')' );
        IF CHARINDEX('%2a', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%2a','*' );
        IF CHARINDEX('%2b', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%2b','+' );
        IF CHARINDEX('%2c', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%2c',',' );
        IF CHARINDEX('%2d', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%2d','-' );
        IF CHARINDEX('%2e', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%2e','.' );
        IF CHARINDEX('%2f', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%2f','/' );
        IF CHARINDEX('%3a', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%3a',':' );
        IF CHARINDEX('%3b', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%3b',';' );
        IF CHARINDEX('%3c', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%3c','<' );
        IF CHARINDEX('%3d', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%3d','=' );
        IF CHARINDEX('%3e', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%3e','>' );
        IF CHARINDEX('%3f', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%3f','?' );
        IF CHARINDEX('%40', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%40','@' );
        IF CHARINDEX('%5b', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%5b','[' );
        IF CHARINDEX('%5c', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%5c','\' );
        IF CHARINDEX('%5d', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%5d',']' );
        IF CHARINDEX('%5e', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%5e','^' );
        IF CHARINDEX('%5f', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%5f','_' );
        IF CHARINDEX('%60', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%60','`' );
        IF CHARINDEX('%7b', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%7b','{' );
        IF CHARINDEX('%7c', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%7c','|' );
        IF CHARINDEX('%7d', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%7d','}' );
        IF CHARINDEX('%7e', @stringAFID ) > 0 SET @stringAFID = Replace(@stringAFID,'%7e','~' );

        --SELECT @stringAFID = Replace(Replace(@stringAFID,'%7e','~' ),'%7d','}' );

    END;

    SET @AfidParse = CAST(@stringAFID AS bigint);

    RETURN @AfidParse;

END;
GO

SELECT dbo.TryParseAFID(34681);