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    ArrayObject::offsetUnset

    (PHP 5, PHP 7, PHP 8)

    ArrayObject::offsetUnset — 指定したインデックスの値を解除する

    説明

    public ArrayObject::offsetUnset(mixed $key): void

    指定したインデックスの値を解除します。

    パラメータ

    key

    解除したいインデックス。

    戻り値

    値を返しません。

    例

    例1 ArrayObject::offsetUnset() の例

    <?php
    $arrayobj     = new ArrayObject(array(0=>'zero',2=>'two'));
    $arrayobj->offsetUnset(2);
    var_dump($arrayobj);
    ?>

    上の例の出力は以下となります。

    object(ArrayObject)#1 (1) {
  [0]=>
  string(4) "zero"
}

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    User Contributed Notes 2 notes

    up
    3
    pvenakis at efront dot gr
    16 years ago
    When traversing recursively nested arrays using an RecursiveIteratorIterator, you cannot offsetUnset() or offsetSet() sub-array values, unless they are *all* declared as ArrayObject.
    up
    0
    oalexandrino at yahoo dot com dot br
    17 years ago
    Be careful when you are working with collections. This method works with the reference of an array instead of its retrieved value.

    So, you can do a mistake.

    In order to understand have a look at code as follow:

    <?php
    class Employee
    {
    public function     __construct()
    {
    }
    }

    class     Company
    {
    private     $arrEmployee;

    public function     __construct()
    {
    }

    public function     AddEmployee(Employee $oEmployee)
    {
    $this->arrEmployee[] = $oEmployee;

    }

    public function     getEmployeeList()
    {
    return     $this->arrEmployee;

    }

    }
    ?>

    <?php

    // first, creates the Company object
    $oCompany = new Company();

    // second, add 10 elements in
    foreach( range(0, 9) as $index )
    {
    $oCompany->AddEmployee( new Employee() );
    }

    // get them
    $arrEmployee = $oCompany->getEmployeeList();

    // creates an ArrayObject from "$arrEmployee"
    $arrayobject = new ArrayObject($arrEmployee);

    // unsets its firt five elements
    foreach( range(0, 4) as $index )
    {
    $arrayobject->offsetUnset($index);
    }

    // get them again
    $arrEmployee = $oCompany->getEmployeeList();

    // it shows just 5 elements, they were removed as reference via "offsetUnset" method
    print_r($arrEmployee) ;

    ?>
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