When traversing recursively nested arrays using an RecursiveIteratorIterator, you cannot offsetUnset() or offsetSet() sub-array values, unless they are *all* declared as ArrayObject.
(PHP 5, PHP 7, PHP 8)
ArrayObject::offsetUnset — Unsets the value at the specified index
keyThe index being unset.
没有返回值。
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"
}
When traversing recursively nested arrays using an RecursiveIteratorIterator, you cannot offsetUnset() or offsetSet() sub-array values, unless they are *all* declared as ArrayObject.
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) ;
?>