Null & Null-Safe Operators

Null & Null-Safe in PHP

isset() & empty()

isset($var) — true if set AND not null
empty($var) — true if falsy (0, "", [], null, false)

Null Coalescing (PHP 7+)

$value = $a ?? "default" — returns $a if set and not null, else "default".

Null-Safe Operator (PHP 8+)

$user?->address?->city — returns null instead of error if any step is null.

Example

<?php
$name = $_GET["name"] ?? "Guest";  // null coalescing
echo "Hello, $name!";

// Null-safe
class User {
    public ?Address $address = null;
}
$user = new User();
echo $user?->address?->city;  // null (no error)

// isset vs empty
$zero = 0;
var_dump(isset($zero));   // true  (it is set)
var_dump(empty($zero));   // true  (0 is falsy)
?>

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