The SplFixedArray class
The SplFixedArray class provides the main functionalities of array. The main difference between a SplFixedArray and a normal PHP array is that the SplFixedArray must be resized manually and allows only integers within the range as indexes. The advantage is that it uses less memory than a standard array.
Intro
The SplFixedArray class provides the main functionalities of array. The main difference between a SplFixedArray and a normal PHP array is that the SplFixedArray must be resized manually and allows only integers within the range as indexes. The advantage is that it uses less memory than a standard array.
Class synopsis
Changelog
| Version | Description |
|---|---|
| 8.4.0 | Out of bounds accesses in SplFixedArray now throw exceptions of type OutOfBoundsException instead of RuntimeException. Because OutOfBoundsException is a child class of RuntimeException no behavioural changes are exhibited when attempting to catch those exceptions. |
| 8.2.0 | The SplFixedArray::__serialize and SplFixedArray::__unserialize magic methods have been added to SplFixedArray. |
| 8.1.0 | Using a non-integer key on a SplFixedArray now throws a TypeError instead of a RuntimeException. |
| 8.1.0 | SplFixedArray implements JsonSerializable now. |
| 8.0.0 | SplFixedArray implements IteratorAggregate now. Previously, Iterator was implemented instead. |
Examples
SplFixedArray usage example
<?php
// Initialize the array with a fixed length
$array = new SplFixedArray(5);
$array[1] = 2;
$array[4] = "foo";
var_dump($array[0]); // NULL
var_dump($array[1]); // int(2)
var_dump($array["4"]); // string(3) "foo"
// Increase the size of the array to 10
$array->setSize(10);
$array[9] = "asdf";
// Shrink the array to a size of 2
$array->setSize(2);
// The following two blocks throw a RuntimeException: Index invalid or out of range
try {
var_dump($array[-1]);
} catch(RuntimeException $e) {
echo "RuntimeException: ".$e->getMessage()."\n";
}
try {
var_dump($array[5]);
} catch(RuntimeException $e) {
echo "RuntimeException: ".$e->getMessage()."\n";
}
// As of PHP 8.1.0, using a non-integer key throws a TypeError.
// Prior to PHP 8.1.0, a RuntimeException was thrown instead.
try {
var_dump($array["non-numeric"]);
} catch(TypeError $e) {
echo "TypeError: ".$e->getMessage()."\n";
}
?>The above example will output:
NULL
int(2)
string(3) "foo"
RuntimeException: Index invalid or out of range
RuntimeException: Index invalid or out of range
TypeError: Illegal offset typePrior to PHP 8.1.0, accessing a SplFixedArray with a non-integer key threw a RuntimeException instead of a TypeError.
Splfixedarray