Final Challenge — Solution

Task: Extend buildProfileCard() to also accept an optional "email" key.
If present and valid (contains an @ character), append a line
"Contact: {email}" to the output; if missing, append "Contact: not
provided" instead. Test it with two different simulated $_POST arrays —
one with a valid email, one without any email key at all — and echo
both results.

<?php
    function formatName($name) {
        return ucwords(trim($name));
    }

    function isValidField($value) {
        return isset($value) && $value !== '';
    }

    function buildProfileCard($profile) {
        $name  = formatName($profile['name'] ?? '');
        $role  = $profile['role'] ?? 'Member';
        $skills = $profile['skills'] ?? [];
        $email = $profile['email'] ?? '';

        if (!isValidField($name)) {
            return "⚠ Cannot build a card — missing name.";
        }

        $skillList = count($skills) > 0
            ? implode(', ', $skills)
            : 'No skills listed';

        $contactLine = (isValidField($email) && str_contains($email, '@'))
            ? "Contact: " . $email
            : "Contact: not provided";

        return sprintf(
            "%s\n%s\nSkills: %s\n%s",
            $name,
            $role,
            $skillList,
            $contactLine
        );
    }

    // Test 1: a profile with a valid email
    $withEmail = [
        'name'   => 'sam taylor',
        'role'   => 'Designer',
        'skills' => ['Figma', 'CSS'],
        'email'  => 'sam@example.com'
    ];
    echo buildProfileCard($withEmail);

    echo "\n\n---\n\n";

    // Test 2: a profile with no email key at all
    $withoutEmail = [
        'name'   => 'alex chen',
        'role'   => 'Backend Engineer',
        'skills' => ['PHP', 'MySQL']
    ];
    echo buildProfileCard($withoutEmail);
?>


Output:
Sam Taylor
Designer
Skills: Figma, CSS
Contact: sam@example.com

---

Alex Chen
Backend Engineer
Skills: PHP, MySQL
Contact: not provided

Notes:
- $profile['email'] ?? '' safely reads the optional key using the same
  null coalescing pattern from Chapter 8 — it evaluates to an empty
  string if "email" was never set at all, rather than triggering an
  undefined-key warning.
- isValidField($email) reuses the exact helper function from
  helpers.php, keeping the "is this field genuinely present and
  non-empty" check consistent with how $name is validated elsewhere in
  the same function.
- str_contains($email, '@') is the Chapter 7 string function doing the
  actual "looks like an email" check — deliberately simple, since full
  email validation is genuinely more involved and out of scope for this
  course.
- The two test cases exercise both branches of the ternary: a present,
  valid email appends the real address, while a completely missing key
  falls all the way through to "Contact: not provided" without any
  warning or error along the way.