Is there an easy way to print out a Perl array with commas in between each element?
Writing a for loop to do it is pretty easy but not quite elegant....if that makes sense.
转载于:https://stackoverflow.com/questions/5741101/easy-way-to-print-perl-array-with-a-little-formatting
Just use join()
:
# assuming @array is your array:
print join(", ", @array);
Also, you may want to try Data::Dumper. Example:
use Data::Dumper;
# simple procedural interface
print Dumper($foo, $bar);
You can use Data::Dump
:
use Data::Dump qw(dump);
my @a = (1, [2, 3], {4 => 5});
dump(@a);
Produces:
"(1, [2, 3], { 4 => 5 })"
If you're coding for the kind of clarity that would be understood by someone who is just starting out with Perl, the traditional this construct says what it means, with a high degree of clarity and legibility:
$string = join ', ', @array;
print "$string\n";
This construct is documented in perldoc -f
join
.
However, I've always liked how simple $,
makes it. The special variable $"
is for interpolation, and the special variable $,
is for lists. Combine either one with dynamic scope-constraining 'local
' to avoid having ripple effects throughout the script:
use 5.012_002;
use strict;
use warnings;
my @array = qw/ 1 2 3 4 5 /;
{
local $" = ', ';
print "@array\n"; # Interpolation.
}
OR with $,:
use feature q(say);
use strict;
use warnings;
my @array = qw/ 1 2 3 4 5 /;
{
local $, = ', ';
say @array; # List
}
The special variables $,
and $"
are documented in perlvar. The local
keyword, and how it can be used to constrain the effects of altering a global punctuation variable's value is probably best described in perlsub.
Enjoy!