Course of Raku / Advanced / Containers / Scalar containers

Proxying method calls

Being a scalar container actually means being an object of the Scalar type. In most cases, the use of scalars is so transparent that a developer does not have to think about the container at all and can imagine working directly with the values stored in it.

This works because a scalar container proxies method calls to the value that it keeps. For example, after the assignment my $lang = 'Raku', you can call the .chars method on the variable:

my $lang = 'Raku';
say $lang.chars; # 4

The program prints 4, which is the number of characters in the string 'Raku'. The result is exactly the same as if you called .chars on the string value directly, rather than on the container variable:

say 'Raku'.chars; # 4

In other words, the container quietly forwards the .chars call to the string it holds, and returns the result to you.

Course navigation

← Default values   |   Default discount →

💪 Or jump directly to the exercises in this section.