xHarbour Reference Documentation > Function Reference

IsAlNum()

Checks if the first character of a string is alpha-numeric.

Syntax

IsAlNum( <cString> ) --> lIsAlphaNumeric

Arguments

<cString>

A character string to check for its first character.

Return

The function returns .T. (true) when the leftmost character of a string is alpha-numeric, otherwise .F. (false).

Description

The function is used to check if a string begins either with a digit, or with an upper or lower case letter from A to Z. It returns .T. (true) when a string begins with an alpha-numeric character, and .F. (false) when it begins with any other character.

Info

See also:	IsAlpha(), IsAscii(), IsCntrl(), IsDigit(), IsGraph(), IsLower(), IsPrint(), IsPunct(), IsSpace(), IsUpper(), IsXDigit(), Lower(), Upper()
Category:	Character functions , xHarbour extensions
Source:	rtl\is.c
LIB:	xhb.lib
DLL:	xhbdll.dll

Example

// The example demonstrates various results of IsAlNum()

   PROCEDURE Main

      ? IsAlNum( "ABC" )               // result: .T.
      ? IsAlNum( "xyz" )               // result: .T.
      ? IsAlNum( "123" )               // result: .T.

      ? IsAlNum( " xHarbour" )         // result: .F.
      ? IsAlNum( ".Net" )              // result: .F.
      ? IsAlNum( "-10" )               // result: .F.
      ? IsAlNum( ".5" )                // result: .F.

   RETURN