Question

I am learning Perl regex, and I am trying to extract digits from a string, e.g.

my $text = "abc000142gh";

i.e. I would like to extract 000142 as a string in a scalar variable.

I have tried:

my $digits = $text ~= /(+d)/;
my $digits = $text ~= m/(+d)/;
my $digits = $text ~= m/(+d)/g;
my $digits = $text ~= /(+d)/g;

but none of them seem to work. Is there a way to do this with a one-liner?

Answer 1

This works:

my $text = 'abc000142gh';
my ($digits) = $text =~ /(\d+)/;

The differences:

1. quotes around the string (not needed, but prefered).
2. $digits in brackets to enforce list context. See perlop for details.
3. The binding operator is =~, not ~=.
4. \d means a digit, d stands for itself.
5. + (repetition) is used after the symbol to repeat, not before.