What is the difference between fetching data as an array and as an object in PHP, and when should each method be used?

When fetching data in PHP, fetching as an array means that the data will be returned as an indexed array where each row is represented by a numeric key. Fetching as an object means that the data will be returned as an object where each row is represented by a property of the object. Fetching data as an array is useful when you need to access data using numeric keys and perform array-specific operations. Fetching data as an object is useful when you prefer to access data using object properties and utilize object-oriented programming features.

// Fetching data as an array
$result = $pdo->query("SELECT * FROM table");
$dataArray = $result->fetchAll(PDO::FETCH_ASSOC);

// Fetching data as an object
$result = $pdo->query("SELECT * FROM table");
$dataObject = $result->fetchObject();