Description:
------------
The Null coalesce operator has an incorrect example. See https://php.net/manual/en/language.operators.comparison.php#language.operators.comparison.coalesce

    <?php
    // Example usage for: Null Coalesce Operator
    $action = $_POST['action'] ?? 'default';
    
    // The above is identical to this if/else statement
    if (isset($_POST['action'])) {
        $action = 'default';
    } else {
        $action = $_POST['action'];
    }
    ?>

Should actually be:

    <?php
    // Example usage for: Null Coalesce Operator
    $action = $_POST['action'] ?? 'default';
    
    // The above is identical to this if/else statement
    if (isset($_POST['action'])) {
        $action = $_POST['action'];
    } else {
        $action = 'default';
    }
    ?>

See this 3v4l for confirmation: https://3v4l.org/H3V7m