The SplFixedArray class
(PHP 5 >= 5.3.0, PHP 7, PHP 8)
簡介
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.
類摘要
/* 方法 */
}更新日誌
| 版本 | 說明 |
|---|---|
| 8.1.0 | SplFixedArray implements JsonSerializable now. |
| 8.0.0 | SplFixedArray implements IteratorAggregate now. Previously, Iterator was implemented instead. |
範例
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";
}
?>
以上例程會輸出：
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
目錄
- 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