array Is Not An Array

<?php

function foo(\array $a) {}

foo([]);

// Fatal error: Uncaught TypeError: foo():
// Argument #1 ($a) must be of type array, array given

?>

PHP native types, such as the scalar int cannot be specified with a leading \. Such code get hit with a Type declaration ‘\int’ must be unqualified.

This is the case for all of the PHP native types, except for array, and iterable.

That error message is really hilarious.

See Also

• Type declaration ‘%s’ must be unqualified

• Array is not an array message [Try me]

PHP Features

• array

• namespace

Last updated: 14 July 2026