I'd like to supplement the suggestions that came from all sides with a little
subroutine which always worked for me determining whether the scalar is a number
(not only integer) and returning the number if it is one. Once having the $res
number from $val variable , you can always test it for being integer, e.g. by
evaluating the expression
 (int abs $res == abs $res)
or, alltogether, checking the $val variable for being integer by the
   (isnumber $val && int abs isnumber $val == abs isnumber $val)
expression.

Cheers,

 --  Andreas

####################################################
# (isn) isnumber
# Returns decimal value of the contents if argument
# is a number (integer if octal or hexadecimal),
# otherwise returns empty string ('')
####################################################
sub isnumber($) {
    local $_ = shift;
    return '' unless /^[+-]?(?:\d+\.?\d*|\.\d+)$|^[+-]?0x[0-9a-fA-F]*$/;
    s/\+//; my $sign = s/^-// ? '-' : '';
    /^0[0-7]*$|^0x[0-9a-fA-F]*$/ ? $sign.oct : $sign.$_*1;
}



To:   "Perl-Unix-Users \(E-mail\)" <perl-unix-users@[...].com> 
      "Perl-Win32-Users \(E-mail\)" <perl-win32-users@[...].com> 
cc:    (bcc: Andreas Kamentz/DE/DELCO)

Subject:  determining if a scalar is an integer or not



Good Day All

How can one determine if a variable is a int or not.

e.g.

my $var1 = 100;
my $var2 = "Hello";

How do I determine if $var1 is an integer and $var2 is a string?

Ronald