The SplFixedArray class
Introduction
(PHP 5 >= 5.3.0, PHP 7, PHP 8)
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
/* Methods */
public count(): int
public current(): mixed
public static fromArray(array $array, bool $preserveKeys = true): SplFixedArray
public getSize(): int
public key(): int
public next(): void
public offsetExists(int $index): bool
public offsetGet(int $index): mixed
public offsetSet(int $index, mixed $value): void
public offsetUnset(int $index): void
public rewind(): void
public setSize(int $size): bool
public toArray(): array
public valid(): bool
public __wakeup(): void}
Changelog
Version | Description |
---|---|
8.1.0 | SplFixedArray implements JsonSerializable now. |
8.0.0 | SplFixedArray implements IteratorAggregate now. Previously, Iterator was implemented instead. |
Examples
Example #1 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 $array->setSize(2); // The following lines throw a RuntimeException: Index invalid or out of range try { var_dump($array["non-numeric"]); } catch(RuntimeException $re) { echo "RuntimeException: ".$re->getMessage()."\n"; } try { var_dump($array[-1]); } catch(RuntimeException $re) { echo "RuntimeException: ".$re->getMessage()."\n"; } try { var_dump($array[5]); } catch(RuntimeException $re) { echo "RuntimeException: ".$re->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 RuntimeException: Index invalid or out of range
Table of Contents
- SplFixedArray::__construct — Constructs a new fixed array
- SplFixedArray::count — Returns the size of the array
- SplFixedArray::current — Return current array entry
- SplFixedArray::fromArray — Import a PHP array in a SplFixedArray instance
- SplFixedArray::getSize — Gets the size of the array
- SplFixedArray::key — Return current array index
- SplFixedArray::next — Move to next entry
- SplFixedArray::offsetExists — Returns whether the requested index exists
- SplFixedArray::offsetGet — Returns the value at the specified index
- SplFixedArray::offsetSet — Sets a new value at a specified index
- SplFixedArray::offsetUnset — Unsets the value at the specified $index
- SplFixedArray::rewind — Rewind iterator back to the start
- SplFixedArray::setSize — Change the size of an array
- SplFixedArray::toArray — Returns a PHP array from the fixed array
- SplFixedArray::valid — Check whether the array contains more elements
- SplFixedArray::__wakeup — Reinitialises the array after being unserialised
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https://www.php.net/manual/en/class.splfixedarray.php