README.md

Description

Function to determine if the passed parameter is AlphaNumeric (the string contains only A-Z, a-z or 1-0). Heavily commented. Bug Fixed.

More Info

The string to be evaluated.

See comments.

Returns True is the string is AlphaNumeric and False if it is not.

Submitted On
By	Ramon Morales
Level	Beginner
User Rating	4.2 (21 globes from 5 users)
Compatibility	ASP (Active Server Pages)
Category	Validation/ Processing
World	ASP / VbScript
Archive File

API Declarations

Public Domain

Source Code

	Function IsAlphaNumeric(sText)
	'***************************************************************************
	'Checks to see if sText is made up of only Alphabetic characters (A-Z) or
	'Numbers. If it has any other characters, IsAlphaNumeric will be False.
	'***************************************************************************
		Dim nLen, nLoop, sTemp,	sSingleCharacter
		Dim bAlphaStatus
	'***************************************************************************
	'Default value
	'***************************************************************************
		bAlphaStatus = True
	'***************************************************************************
	'Gets length of the sText variable.
	'***************************************************************************
		sTemp = Trim(sText)
		nLen = Len(sTemp)
	'***************************************************************************
	'If the length of sText is 0, then it is not AlphaNumeric and
	'IsAlphaNumeric = False.
	'***************************************************************************
		If nLen = 0 then
			bAlphaStatus = False
		End If	'If nLen = 0 then
		If nLen > 0 then
	'***************************************************************************
	'Convert sText to uppercase to make comparisons easier.
	'***************************************************************************
			sTemp = Ucase(sTemp)
	'***************************************************************************
	'Will loop nLen times. It will check each of the characters of sText against
	'the comparison string (which is A-Z and 1-0). It will check it one
	'character at a time (beginning with the farthest left character).If the
	'Instr command shows a 0 (meaning it could not find a match), that character
	'was not AlphaNumeric.
	'***************************************************************************
			For nLoop =1 to nLen
				sSingleCharacter = Mid(sTemp,nLoop,1)
				If Instr("ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890", sSingleCharacter)= 0 then
					bAlphaStatus = False
					Exit For
				End If
			Next
	'***************************************************************************
	'If sText managed to get through the above filters without changing
	'IsAlphaNumeric to False, then IsAlphaNumeric is True.
	'***************************************************************************
			If bAlphaStatus <> False then
				bAlphaStatus = True
			End If
		End If	'If nLen > 0 then
		IsAlphaNumeric = bAlphaStatus
	End Function