The SplFixedArray class

    (PHP 5 >= 5.3.0, PHP 7, PHP 8)

    简介

    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.

    类摘要

    class SplFixedArray implements IteratorAggregate, ArrayAccess, Countable, JsonSerializable {
    /* 方法 */
    public __construct(int $size = 0)
    public count(): int
    public current(): mixed
    public static fromArray(array $array, bool $preserveKeys = true): SplFixedArray
    public getIterator(): Iterator
    public getSize(): int
    public jsonSerialize(): array
    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 __serialize(): array
    public setSize(int $size): bool
    public toArray(): array
    public __unserialize(array $data): void
    public valid(): bool
    public __wakeup(): void
    }

    更新日志

    版本 说明
    8.2.0 The SplFixedArray::__serialize() and SplFixedArray::__unserialize() magic methods have been added to SplFixedArray.
    8.1.0 SplFixedArray implements JsonSerializable now.
    8.0.0 SplFixedArray implements IteratorAggregate now. Previously, Iterator was implemented instead.

    示例

    示例 #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";
    }
    ?>

    以上示例会输出：

    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

    目录

    Improve This Page

    Learn How To Improve This Page • Submit a Pull Request • Report a Bug
    ＋add a note

    User Contributed Notes

    There are no user contributed notes for this page.
    To Top