This is a prime example of why I preach so heavily about use strict;. If you had invoked that pragma you'd have seen the warning:

Use of uninitialized value $_ in print at sopw-simple.pl line 6.
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In Perl, several functions and operators use this variable as a default, in case no parameter is explicitly used. In general, I'd say you should NOT see $_ in real code. I think the whole point of $_ is that you don't have to write it explicitly.

Well, except when you do.

Having a default variable is a very powerful idea, but using it incorrectly can reduce the readability of your code.

$_ = "TestA" or "TestB";
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Found = in conditional, should be == at ./sopw-simple.pl line 4.
Useless use of a constant (TestB) in void context at ./sopw-simple.pl 
+line 4.
TestA
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My suggestion is read the web page I provided above for some hints on what you can and can't do with $_. Just a thought...

"This is a prime example of why I preach so heavily about use strict;. If you had invoked that pragma you'd have seen the warning:

"Use of uninitialized value $_ in print at sopw-simple.pl line 6."

Nuh-uh... strict does no such thing.

strict does three things:

• Throws compile-time errors for undeclared variables.
• Throws compile-time errors when barewords are seen which don't correspond to subs, and don't look like the package name in a class method call.
• Throws run-time errors when symbolic references are used, or more generally when trying to dereference a variable which does not contain a reference.

strict never issues any warnings. And strict doesn't care about variables being undef (unless you try to dereference them).

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

Nuh-uh... strict does no such thing.

Really? That's a copy/paste from my terminal. Wish there was a way to post screenshots to PM.

---

Peter L. Berghold -- Unix Professional
Peter -at- Berghold -dot- Net; AOL IM redcowdawg Yahoo IM: blue_cowdawg

Despite all correct (!!) advices given before:

print for ("Test A" or "Test B");
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Best regards
McA

Your code:

"Test A"or"Test B";
print;
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Hi, I am unsure about what you are trying to achieve here as there is very little of the code.

$_ is a global variable and quite a few places in perl use $_ as the default.

To know more use 'perldoc perlvar' and you will have a good explanation of where and how $_ can be used.

I hope this helps.

Arnaud.

use strict;
use warnings;
use autodie;

while(<DATA>) {
    print;
}

__DATA__
Test A
Test B
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$_ = ("Test A" or "Test B");
print;
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I'm trying to get "Test A"

(Yes, you are doing wrong) Is "Test A" a six character's string, a filehandle, a variable, a macguffin?

We simply need some more clues