Course of Raku / Advanced / Subroutines / Signatures / Exercises / An optional exponent

Solution: An optional exponent

Here is a possible solution to the task.

Code

sub power($base, $exp?) {
    $base ** ($exp // 2)
}

say power(5);
say power(5, 3);

🦋 You can find the source code in the file optional-exponent.raku.

Output

25
125

Comments

1. The ? after $exp makes it optional, so power can be called with just the base.

2. When $exp is omitted it is undefined, and // supplies the fallback 2, so power(5) squares the base to 25. Given an exponent, as in power(5, 3), that value is used instead, giving 125.

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