ArrayObject::__construct

(PHP 5, PHP 7, PHP 8)

ArrayObject::__construct — Construct a new array object

说明

public ArrayObject::__construct(array|object $array = [], int $flags = 0, string $iteratorClass = ArrayIterator::class)

This constructs a new array object.

参数

array: The array parameter accepts an array or an Object.
flags: Flags to control the behaviour of the ArrayObject object. See ArrayObject::setFlags().
iteratorClass: Specify the class that will be used for iteration of the ArrayObject object. The class must implement Iterator.

范例

示例 #1 ArrayObject::__construct() example


<?php
$array = array('1' => 'one',
               '2' => 'two',
               '3' => 'three');

$arrayobject = new ArrayObject($array);

var_dump($arrayobject);
?>

以上例程会输出：

object(ArrayObject)#1 (3) {
  [1]=>
  string(3) "one"
  [2]=>
  string(3) "two"
  [3]=>
  string(5) "three"
}

参见

ArrayObject::setflags() - Sets the behavior flags

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User Contributed Notes 4 notes

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german dot rumm at gmail dot com ¶

14 years ago


BTW, if you need to change array later, use exchangeArray() method. Good to know when you are writing a class that extends ArrayObject()

AFAIK, exchangeArray() doesn't return anything.

<?php
    $a = array('one', 'two', 'three');
    $ao = new ArrayObject($a);

    foreach ($ao as $element) {
        echo $element . ' '; // one two three
    } 

    $b = array('four', 'five', 'six');
    $ao->exchangeArray($b); // returns null

    foreach ($ao as $element) {
        echo $element . ' '; // four five six
    }
?>

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-4

ashley at nospam dot zincdigital dot com ¶

12 years ago


The great confusion with this class is in its naming.  ArrayObject infers it will behave as an Array and as an Object.  It won't.  It behaves as an array.  It would better be called ArrayType.  You can, with some work, get it to work both as an object and as an array, but that is up to you.

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-5

Grigori Kochanov ¶

15 years ago


As Marcus explained, the flag ArrayObject::SPL_ARRAY_AS_PROPS means the array element may be used as a property if there is no conflict with visible properties.


If there are visible properties in the class, the array element will not overwrite it's value.


<?php

class Rules extends ArrayObject {

    public $len = 1;

    function __construct($array){

        parent::__construct($array,ArrayObject::ARRAY_AS_PROPS);

        $this['len'] = 2;

    }

}

$x = new Rules(array(1,2));

echo $x->len;

?>

Result: 1


<?php

class Rules extends ArrayObject {

    private $len = 1;

    function __construct($array){

        parent::__construct($array,ArrayObject::ARRAY_AS_PROPS);

        $this['len'] = 2;

    }

}

$x = new Rules(array(1,2));

echo $x->len;

?>

Result: 2

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-9

agalkin at agalkin dot ru ¶

14 years ago


Note that the first argument to ArrayObject::__construct, the initial array, is passed by reference. Nevertheless, modification of the array doesn't modify the object, so it may cause unexpected behaviour.

<?php
$array = array('foo' => 'initial');
$obj = new ArrayObject($array);

// array was passed by reference:
$obj['foo'] = 'modified';
var_dump($array); // foo => modified

// but it doesn't work backwards:
$array['foo'] = 'modified_again';
var_dump($obj); // foo => modified
var_dump($array); // foo => modified_again
?>

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