The Array variables (i.e., all the variables starting with the @ sigil) are equipped with a couple of simple but rather useful methods.
my @a = 1, 2, 3, 5, 7, 11; say @a.Int; # array length say @a.Str; # space-separated values
If you print an array, you get its value as a space-separated list in square brackets. Alternatively, you may interpolate it in a string.
my @a = 1, 2, 3, 5, 7, 11; say @a; # [1 2 3 5 7 11] say "This is @a: @a[]"; # This is @a: 1 2 3 5 7 11