The $[ Special Variable in Perl

Perl provides numerous special variables, which have their predefined meaning.

We have a special variable, which is written as $[. This special variable is a scalar containing the first index of all arrays. Because Perl arrays have zero-based indexing, $[ will almost always be 0. But if you set $[ to 1 then all your arrays will use on-based indexing. It is recommended not to use any other indexing other than zero. However, let's take one example to show the usage of $[ variable −

Example

 Live Demo

#!/usr/bin/perl
# define an array
@foods = qw(pizza steak chicken burgers);
print "Foods: @foods\n";
# Let's reset first index of all the arrays.
$[ = 1;
print "Food at \@foods[1]: $foods[1]\n";
print "Food at \@foods[2]: $foods[2]\n";

Output

This will produce the following result −

Foods: pizza steak chicken burgers
Food at @foods[1]: pizza
Food at @foods[2]: steak