Challenge 2 — Solution

Task: Create a custom exception InvalidAgeException extending
Exception. Write a function setAge($age) that throws it if age is below
0 or above 130, otherwise echoes "Age set to $age." Test it with a
try/catch/finally, where the finally block always echoes "Validation
attempt complete."

<?php
    class InvalidAgeException extends Exception {}

    function setAge(int $age) {
        if ($age < 0 || $age > 130) {
            throw new InvalidAgeException("$age is not a valid age.");
        }
        echo "Age set to $age.<br>";
    }

    try {
        setAge(200);
    } catch (InvalidAgeException $e) {
        echo "Invalid age: " . $e->getMessage() . "<br>";
    } finally {
        echo "Validation attempt complete.";
    }
?>


Output:
Invalid age: 200 is not a valid age.
Validation attempt complete.

Notes:
- InvalidAgeException extends the built-in Exception with an empty body
  - it inherits everything Exception already provides (including
  getMessage()) purely through inheritance, needing no extra code of
  its own.
- setAge(200) throws immediately since 200 is above the 130 upper
  bound, so the "Age set to..." success line inside setAge() never
  runs at all.
- "Validation attempt complete." prints regardless of whether setAge()
  succeeded or threw - if setAge(45) had been called instead, the
  catch block would be skipped entirely, but finally would still run
  and print the identical closing line.