ArrayObject::offsetUnset

(PHP 5, PHP 7, PHP 8)

ArrayObject::offsetUnset — Unsets the value at the specified index

说明

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

Unsets the value at the specified index.

参数

key: The index being unset.

返回值

没有返回值。

范例

示例 #1 ArrayObject::offsetUnset() example


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

以上例程会输出：

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

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User Contributed Notes 2 notes

down

pvenakis at efront dot gr ¶

14 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.

down

oalexandrino at yahoo dot com dot br ¶

15 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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官方地址：https://www.php.net/manual/en/arrayobject.offsetunset.php

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PHP官方手册 - 互联网笔记

ArrayObject::offsetUnset

说明

参数

返回值

范例

User Contributed Notes 2 notes