How can PHP's built-in functions like print_r and mysql_affected_rows be effectively utilized in array processing and database updates?

To effectively utilize PHP's built-in functions like print_r and mysql_affected_rows in array processing and database updates, you can use print_r to debug and display the contents of an array, helping you understand its structure and values. Similarly, mysql_affected_rows can be used to determine the number of rows affected by a database update query, allowing you to verify the success of the operation.

// Example of utilizing print_r in array processing
$array = [1, 2, 3, 4, 5];
print_r($array);

// Example of utilizing mysql_affected_rows in database updates
$query = "UPDATE table SET column = 'new_value' WHERE condition";
$result = mysql_query($query);
$rows_affected = mysql_affected_rows();
echo "Rows affected: " . $rows_affected;