SplFixedArray::fromArray

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

SplFixedArray::fromArray — Import a PHP array in a SplFixedArray instance

说明

public static SplFixedArray::fromArray(array $array, bool $preserveKeys = true): SplFixedArray

Import the PHP array array in a new SplFixedArray instance

参数

array: The array to import.
preserveKeys: Try to save the numeric indexes used in the original array.

返回值

Returns an instance of SplFixedArray containing the array content.

范例

示例 #1 SplFixedArray::fromArray() example


<?php
$fa = SplFixedArray::fromArray(array(1 => 1, 0 => 2, 3 => 3));

var_dump($fa);

$fa = SplFixedArray::fromArray(array(1 => 1, 0 => 2, 3 => 3), false);

var_dump($fa);
?>

以上例程会输出：

object(SplFixedArray)#1 (4) {
  [0]=>
  int(2)
  [1]=>
  int(1)
  [2]=>
  NULL
  [3]=>
  int(3)
}
object(SplFixedArray)#2 (3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
}

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User Contributed Notes 1 note

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MuLoT ¶

11 years ago


Memory footprint tests : 


<?php

echo memory_get_usage()."\n"; // display 627760

$array = array_fill( 0, 2048, 'a' );

echo memory_get_usage()."\n"; // 824744, so 196984 for $array


unset( $array );


echo memory_get_usage()."\n"; // 627792

$spl=SplFixedArray::fromArray( array_fill( 0, 2048, 'a' ) );

echo memory_get_usage()."\n"; //644944, so just 17151 for $spl !!!

?>

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备份地址：http://www.lvesu.com/blog/php/splfixedarray.fromarray.php