Course of Raku / Essentials / Code blocks

Lexical scope

A code block creates a so-called lexical scope. Variables declared in the current block are visible inside it, but not after the program exits the block. Consider an example:

{
    my $x = 42;
    say $x;
}

say $x;

The $x variable is created in the code block. The first call of say $x prints the value of the variable as it is visible within the block. The second say $x fails because the name $x does not exist outside of the block and is not known after it ended. The program does not compile and you get an error:

===SORRY!=== Error while compiling /Users/ash/raku-course/t.raku
Variable '$x' is not declared
at /Users/ash/raku-course/t.raku:6
------> say ⏏$x;

Practice

Complete the quiz that covers the contents of this topic.

Course navigation

← Code blocks   |   Code blocks / Global variables →