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ArrayObject::offsetUnset

(PHP 5, PHP 7)

ArrayObject::offsetUnsetUnsets the value at the specified index

说明

public void ArrayObject::offsetUnset ( mixed $index )

Unsets the value at the specified index.

参数

index

The index being unset.

返回值

没有返回值。

范例

Example #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

up
1
pvenakis at efront dot gr
10 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
10 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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