SPUG: Re: Counting the number of instances in a string using Perl's

Aaron Fossum fossumar at hotmail.com
Mon Dec 18 14:25:20 CST 2000

I think there's a recipe for this in the Perl Cookbook, but my copy's not handy here. :)

while( $string =~ /yourstringhere/g ) {

should work.

Aaron Fossum

----- Original Message -----
From: Jonathan Gardner
Sent: Monday, December 18, 2000 12:02 PM
To: spug-list at pm.org
Subject: SPUG: Counting the number of instances in a string using Perl's

Say I had a string with a whole bunch of characters - "asdfjkhafjklhaf".

How would I go about counting the number of individual characters (say,

One way I found in the book is this:
@arr = $string =~ m/a/g;
$number_of_a = scalar @arr;

Is there a more elegant way of going about this? I want to skip the creation
of @arr (I am worried about performance. The actual thing I will match is a
little big and will take some time to write to an array.) I have a gut
feeling that there is, and I just don't know what it is yet...

BTW, it's not:
$number = scalar $string =~ m/a/g;
$number = scalar ($string =~ m/a/g);

This use of scalar forces the function (m//) to return a scalar not an
array. It doesn't take the array we want so badly and count the number of

Jonathan M. Gardner
CarDomain Networks
(425)820-2244 x23
gardner at sounddomain.com

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