ArrayObject
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ArrayObject::offsetUnset

(PHP 5 >= 5.0.0)

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"
}


ArrayObject
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用户评论:

pvenakis at efront dot gr (2008-01-10 00:57:17)

When traversing recursively nested arrays using an RecursiveIteratorIterator, you cannot offsetUnset() or offsetSet() sub-array values, unless they are *all* declared as ArrayObject.

oalexandrino at yahoo dot com dot br (2007-05-28 11:11:11)

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(09) 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(04) 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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