Re: string to number via data dumper

[Happy-the-monk]

Fortunately, Perl will convert your string back to a number whenever you treat it as one.
like say $stuff + 0 ; # print $stuff + 0 , "\n" ; # on older perl versions.

I also believe Data::Dumper did not convert your number to a string but added quotes for clarity.

Cheers, Sören

[Anonymous Monk]

I also believe Data::Dumper did not convert your number to a string but added quotes for clarity.

Yep, it simply quoted the strings -- a string is not a number until its treated like a number :)

$ perl -MData::Dump -e " dd '+11', 0+ '+11' "
("+11", 11)

[semipro]

Hi there, thank you. While treating the output as number so eg:

#!/usr/bin/perl -w
use strict;

my $resultnow='C:/Users/user/Desktop/solution.dat';

open (FILE, '<', $resultnow) or die "$resultnow File not found : $!";
my @lines = <FILE>;

my $valuenow= $lines[9];

my @items=split' ',$valuenow;



use Data::Dumper;



#print Dumper(@items);
my $val=Dumper("$items[-1]");


my $n= "$val+8";
print $n;

close (FILE);

here I tryed to make a sum. with "my $n= "$val+8";", so that I can obtain a vlue like -31.9999400000 (instead of '-39.9999400000'+8). But unfortunately that does not work. So how can I solve this problem? (that was the reason why I thought it is a string value).

[kcott]

"here I tryed to make a sum. with "my $n= "$val+8";", so that I can obtain a vlue like -31.9999400000 (instead of '-39.9999400000'+8). But unfortunately that does not work. So how can I solve this problem? (that was the reason why I thought it is a string value)."

I know you've only been using Perl for a short amount of time, but I don't think you've really got an understanding of the basics. Try reading "perlintro -- a brief introduction and overview of Perl": you need a solid foundation on which to build further knowledge.

With regard to your "$val+8" question, this code should explain why it's not working:

#!/usr/bin/env perl -l

use strict;
use warnings;

my @items = (-39.9999400000);
my $val = $items[-1];
print $val;

my $n = "$val+8";
print $n;

my $x = $val+8;
print $x;

Output:

-39.99994
-39.99994+8
-31.99994

[Laurent_R]

Ken said it all, but just in case you have trouble understanding his example, just change:

my $n= "$val+8";
print $n;

to:

my $n= $val+8;
print $n;

In the first code snippet above, you are constructing a string composed of the concatenation of your value (in string form) and the "+8" string. In other words, you are just doing string manipulation, no arithmetics. The second code snippet is actually adding the number 8 to your value. Now, if you understood the difference, go back to Ken's example.