I believe checking a regex for failure can prevent many headaches later.
#!/usr/bin/perl
use strict;
use warnings;
my $problem = '1 / 2 = ';
my ($number1, $number2, $operator);
if ($problem =~ /(\d+)\s*([-+*\/])\s*(\d+)/){
($number1, $number2, $operator) = ($1, $2, $3);
print "$number1 $number2 $operator\n";
}
else{
print "regex failed\n";
}
I also agree with monarch that as you know what the operator can be you can use a character class.
FWIW. I always have to check the docs to check which characters need escaping. They say that:
The special characters for a character class are -]\^$ and are matched using an escape...
Now I'm sure that's a backslash in there. But I couldn't get the regex above to work without escaping the forward slash.
Anyone see what I'm missing here?
Update:
It's because I used the forward slash as the quote for the regex!
Many thanks to the monks in the CB.
In reply to Re: '+' to +
by wfsp
in thread '+' to +
by NateTut
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