将正则表达式存储在变量中，然后找到pattern（Perl）？

Question

Hi I have problem with regular expression in Perl. If i store the regular expression in variable in perl it is not able to match. Why its like that? How can i resolve this issue? Below is my code which prints Failed as output:

my $str1 = 'abc..';
my $str2 = 'abcde';

my $pcode = $str1;

print $pcode;

if( $pcode =~ /$str2/)
{
    print "Got";
}
else
{
    print "Failed";
}

Answer 1

You need to invert your logic. The regex goes inside the // , not the string.

Give your variables better names, and it becomes more apparent when you've inverted your logic like that.

my $pattern = 'abc..';
my $string = 'abcde';

if ($string =~ /$pattern/) {
    print "Got";
} else {
    print "Failed";
}

Answer 2

Your if( $pcode =~ /$str2/) is in the wrong order. You need to change it:

if( $str2 =~ /$pcode/)

Basically, $pcode contains the Pattern, so its inside the // and the string which you want to check against a pattern comes in front of the =~