In Control flow§

See primary documentation in context for given.

The given statement is Raku's topicalizing keyword in a similar way that switch topicalizes in languages such as C. In other words, given sets $_ inside the following block. The keywords for individual cases are when and default. The usual idiom looks like this:

my $var = (Any, 21, any <answer lie>).pick;
given $var {
    when 21 { say $_ * 2 }
    when 'lie' { .say }
    default { say 'default' }
}

The given statement is often used alone:

given 42 { .say; .Numeric; }

This is a lot more understandable than:

{ .say; .Numeric; }(42)