perl5-string-interpolation.pl

#!/usr/bin/env perl
use v5.20.3;
use strict;
use warnings;

# Basic String Interpolation with Scalars and Lists
my $PI   = 3.14;
my @nums = (3, 2, 1);

say "scalar: $PI - list: @nums";
say "scalar: ${ PI } - list: @{ nums }";
say q();


# String Interpolation with Constants
use constant DEV_OPS => 'dev_ops';
my $status = 'online';

say "Team ${ \DEV_OPS } is ${ status }";
# or if we use more than one constant
say "Team ${ \DEV_OPS } - ${ \DEV_OPS } is ${ status }";
say q();


# Using Constants with Regular Expressions
use constant BLUE  => 'blue';
use constant GREEN => 'green';
use constant RED   => 'red';

use constant COLORS_REGEXP => qr/^(
    ${\BLUE}  |
    ${\GREEN} |
    ${\RED}
)$/x;

my @colors = qw(blue yellow orange red);

say $_ =~ COLORS_REGEXP
    ? "$_ is valid"
    : "$_ is invalid" foreach @colors;