presence-checks.md

Presence checks

Goal: test whether a key exists in a source without reading its value.

public function hasGet(string $key): bool;
public function hasPost(string $key): bool;
public function hasRaw(string $key): bool;

Each is the equivalent of array_key_exists() against its source — and, like array_key_exists(), a key whose value is null still counts as present.

Working example

use InitPHP\Input\Inputs;

$input = new Inputs(
    get:  ['debug' => '1', 'note' => null],
    post: ['email' => 'jane@example.com'],
    raw:  ['token' => 'abc'],
);

$input->hasGet('debug');  // true
$input->hasGet('note');   // true  — present even though the value is null
$input->hasGet('email');  // false — that key is in post, not get

$input->hasPost('email'); // true
$input->hasRaw('token');  // true
$input->hasRaw('debug');  // false

Presence vs. truthiness

hasGet() answers "is the key there?", not "does it hold a useful value?". Use it to distinguish an absent field from one submitted empty:

$input = new Inputs(get: ['newsletter' => '']);

$input->hasGet('newsletter');        // true — the checkbox was submitted
$input->get('newsletter') === '';    // true — but it is empty

Expected output

Call	Result
hasGet('note')	true
hasGet('email')	false
hasRaw('token')	true

Common mistakes

• Assuming case-insensitivity. hasGet('Debug') is false when the key is debug. Keys are case-sensitive.
• Using presence as a truthiness test. A present key can still be an empty string. Combine with a value read or a required rule when you need a non-empty value.

Next

• The facade
• Reading sources