xHarbour Reference Documentation > Function Reference

IsDigit()

Checks if the first character of a string is a digit.

Syntax

IsDigit( <cString> ) --> lIsDigit

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 a digit, otherwise .F. (false).

Description

The function is used to check if a string begins with a digit. It returns .T. (true) when a string begins with a digit, and .F. (false) when it begins with any other character.

Info

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

Example

// The example demonstrates various results of IsDigit()

   PROCEDURE Main

      ? IsDigit( "ABC" )               // result: .F.
      ? IsDigit( " 10" )               // result: .F.

      ? IsDigit( "10" )                // result: .T.
      ? IsDigit( ".1" )                // result: .F.
      ? IsDigit( "-1" )                // result: .F.

   RETURN