PHP Manual: Constructs a new fixed array

public SplFixedArray::__construct(int $size = 0)

Initializes a fixed array with a number of null values equal to size.

size: The size of the fixed array. This expects a number between 0 and PHP_INT_MAX.

Throws a ValueError when size is a negative integer.

Version	Description
8.0.0	Now throws a ValueError if `size` is a negative; previously it threw a InvalidArgumentException.

Example #1 SplFixedArray::__construct example

<?php
$array = new SplFixedArray(5);

$array[1] = 2;
$array[4] = "foo";

foreach($array as $v) {
  var_dump($v);
}
?>

The above example will output:

NULL
int(2)
NULL
NULL
string(3) "foo"