shan_emails has asked for the wisdom of the Perl Monks concerning the following question:

Dear Monks,

How can i print the variable. my coding is
my $KPI0=10;
my $KPI1=20;
my $KPI2=30;
my $KPI3=40;
my $KPI4=50;

      for($i=0;$i<5;$i++){
        my $var="$KPI$i";
        print "line"."$var"."\n";
      }

my expected output is  
line10
line20
line30
line40
line50

[download]


Thanks in advance
Shanmugam A.

Replies are listed 'Best First'.
Re: how can print the variable values
by Corion (Patriarch) on Dec 01, 2008 at 11:29 UTC
[reply]
Re: how can print the variable values
by ccn (Vicar) on Dec 01, 2008 at 11:28 UTC

    You should better to use an array 

    my @KPI = (10, 20, 30, 40, 50);

for my $i (0 .. $#KPI){
    my $var = $KPI[$i];
    print "line"."$var"."\n";
}

    [download]
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Re: how can print the variable values
by oko1 (Deacon) on Dec 01, 2008 at 13:32 UTC

    General rule of thumb: whenever you find yourself creating a collection of variables, you should use a hash (or occasionally an array) instead. Also, when you find yourself using a C-style 'for(;;)' loop, you should consider whether it's actually the right thing. Most times, it's not. 

    ### Array
# Indexes of 0-4 automatically assigned by Perl!
my @kpi = qw/10 20 30 40/;
print "line$kpi[$_]\n" for 0..4;

### Hash
my %kpi;
# Populating via hash slice to save typing
@kpi{0..4} = qw/10 20 30 40 50/;
print "line$kpi{$_}\n" for 0..4;

    [download]

    --
    "Language shapes the way we think, and determines what we can think about."
    -- B. L. Whorf
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Re: how can print the variable values
by JavaFan (Canon) on Dec 01, 2008 at 13:02 UTC
    Well, one of doing this (although I strongly recommend against this practise - not just this way, but using "names of variables" to get to the variables value in general) is: 
    use warnings;
use strict;
our $KPI0 = 10;
our $KPI1 = 20;
our $KPI2 = 30;
our $KPI3 = 40;
our $KPI4 = 50;
for (my $i = 0; $i < 5; $i++) {
    my $var = "KPI$i";
    no strict 'refs';
    print "line", $$var, "\n";
}

    [download]
    But I can't imagine why you want it this way. Use an array or a hash: 
    use strict;
use warnings;
my @KPI = (10, 20, 30, 40, 50);
for (my $i = 0; $i < @KPI; $i++) {
    print "line", $KPI[$i], "\n";
}

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Re: how can print the variable values
by linuxer (Curate) on Dec 01, 2008 at 12:41 UTC

    Why do you want to stick to symbolic references?

    What's the problem using a hash or an array?

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Re: how can print the variable values
by dharanivasan (Scribe) on Dec 01, 2008 at 13:26 UTC
    Better you can use array. 
    use strict;
use warnings;

our $KPI0=10;
our $KPI1=20;
our $KPI2=30;
our $KPI3=40;
our $KPI4=50;

print ${$main::{"KPI$_"}}."\n" foreach(0..4);

    [download]
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