Match the one or more alphanumerics.

    

$p = "This is a pattern test.";

if ($p =~ /(\w)*/){ print "$1\n"; }

if ($p =~ /(\w)+/){ print "$1\n"; }

1.	Determine if a string has a digit.
2.	Check for no digit
3.	Check for digit
4.	if ($text =~ /(\d+)/) {print "Here's the number of apples: $1.\n";}
5.	if ($text =~ /\D/) {print "It's not a number.";}
6.	if ($text =~ /^[+-]\d+\.\d*$/) {print "It's a number.";}
7.	if ($text =~ /^\d+$/) {print "It's a number.";}
8.	A simple integer-validation program.
9.	Get all numbers
10.	Match numbers
11.	Matching Any Letter or Number
12.	Match one or zero alphanumerics followed by a single space character

Match the one or more alphanumerics. : Digit « Regular Expression « Perl