Re: Barewords equal zero?

An example for the lazy folks out there, that demonstrates (for beginners) why warnings would be useful in addition to strict.

using strict only

use strict; 

my $string = 'hello world'; 
print substr($string,'O',5)."\n";
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Output doesn't really scream don't use the letter O:

perl absurd.pl
hello
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using strict and warnings

use strict; 
use warnings;

my $string = 'hello world'; 
print substr($string,'O',5)."\n";
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Useful output with some notes on what should be a number and isn't:

perl absurd.pl
Argument "O" isn't numeric in substr at absurd.pl line 4.
hello
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Comment on Re: Barewords equal zero? Select or Download Code

Replies are listed 'Best First'.
Re^2: Barewords equal zero? by ikegami (Patriarch) on Feb 12, 2008 at 21:12 UTC
I noticed you changes the OP's code to something that strict wouldn't catch... But you're right. strict will catch some things. warnings will catch others. Both have their uses.	[reply]
Re^3: Barewords equal zero? by rgiskard (Hermit) on Feb 13, 2008 at 15:47 UTC
In the previous example, I put quotes around the capital letter O. Because, quite frankly, barewords are painful. It's also important to look at it from the perspective of someone fixing the barewords but not fixing the real problem, as some may read the capital letter O and think it to be a zero (0) and brute force the solution by getting rid of the barewords by quoting everything. So without warnings, there's no difference between a quoted letter O and a quoted number 0. If one is starting out with the language then hopefully I've pointed out some positives about strict and warning. example with a quoted number zero `use strict; use warnings; my $string = 'hello world'; print substr($string,'0',5)."\n";` [download] output `sh-3.2$ perl absurd2.pl hello` [download]	[reply] [d/l] [select]