Question

I have an element in an array that I’d like to move accordingly.

@array = ("a","b","d","e","f","c");

Basically I’d like to find the index of “c” and then place it before “d” again based on “d”‘s index. I’m using these characters as an example. It has nothing to do with sorting alphabetically.

Answer 1

Try doing this using array slice and List::MoreUtils to find array elements indexes :

use strict; use warnings;
use feature qw/say/;

# help to find an array index by value
use List::MoreUtils qw(firstidx);

my @array = qw/a b d e f c/;

# finding "c" index
my $c_index = firstidx { $_ eq "c" } @array;

# finding "d" index
my $d_index = firstidx { $_ eq "d" } @array;

# thanks ysth for this
--$d_index if $c_index < $d_index;

# thanks to Perleone for splice()
splice( @array, $d_index, 0, splice( @array, $c_index, 1 ) );

say join ", ", @array;

See splice()

OUTPUT

a, b, c, d, e, f