in reply to Re: Floating point number counting script stuck in a loop
in thread Floating point number counting script stuck in a loop

I see, thanks. This compiles and runs properly: 
#!/usr/bin/perl

$count = .0;

while ($count < .9)
{
    $count = $count + .1;

    print ($count, "\n");
}

print ("End!\n");

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But when I use -w and use strict; I get those same compilation errors. What is an explicit package name? What I've found about this error is that it has something to do with having not declared a variable you're trying to use under -w or use strict;, but I've declared my only variable. I don't suppose it especially matters if it compiles at all, but I'm curious now.

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Re^3: Floating point number counting script stuck in a loop
by dwu (Monk) on Oct 25, 2007 at 08:03 UTC
    When using strict (which is a good thing), declaring variables happens like this: 
    my $count;

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    Technically, you've initialised a variable, not declared it. Doing both at the same time: 
    my $count = 0.0;

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    Update: This link may prove helpful.
    Declaring variables
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[d/l]
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      Ooh, thanks, that's wonderful. I assumed a variable was declared by being assigned a value in the first place.
      Cheers. :D
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Re^3: Floating point number counting script stuck in a loop
by GrandFather (Saint) on Oct 25, 2007 at 08:06 UTC

    When you use strict; (highly recommended btw.) you need to declare your variables so you need to stick my in front of the first assignment to $count. However, I'd be inclined to use a C type for loop in this case (note the declaration inside the loop header):

    use strict;
use warnings;

for (my $count = 0.0; $count < 0.9; $count += 0.1) {
    print "$count\n";
}

print "End!\n";

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    Note too that print doesn't need () and that variables can be interpolated directly into double quoted strings.

    Perl is environmentally friendly - it saves trees
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[d/l]
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      Huh, I wonder why the tutorial uses (), then? Do they have any purpose or does it just make things look nice, what with all the rounded-off ends? XD

      Thanks for that, by the way, I've always wanted to be able to compress scripts to be painfully tiny. (No sarcasm, it really does look impressive).

      I did read that variables can be put in strings and I had it that way at the beginning, but I thought it might have been the problem and never changed it back after I tested that.

      Thanks for the help.
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        Tinyish (but most on perlmonks can do better than I): 
        #!/usr/bin/perl -w
use strict;

for (1..9) {
  print $_/10, "\n";
}

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        Does the same as the question asks - likely wouldn't have accomplished the aim of the exercise, which was probably to teach you about using == with floats, but well ;) See perlvar for explanation of $_
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[d/l]

        Then you might like:

        #!/user/bin/perl -w
use strict;
use warnings;

print "@{[$_/10]}\n" for 0 .. 9;
print "End!\n";

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        Perl is environmentally friendly - it saves trees
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[d/l]

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