PHP 5.4.31 Released

Introdução

Weak references provide a non-intrusive gateway to ephemeral objects. Unlike normal (strong) references, weak references do not prevent the garbage collector from freeing that object. For this reason, an object may be destroyed even though a weak reference to that object still exists. In such conditions, the weak reference seamlessly becomes invalid.

Exemplo #1 Weakref usage example

<?php
class MyClass {
    public function 
__destruct() {
        echo 
"Destroying object!\n";
    }
}

$o1 = new MyClass;

$r1 = new Weakref($o1);

if (
$r1->valid()) {
    echo 
"Object still exists!\n";
    
var_dump($r1->get());
} else {
    echo 
"Object is dead!\n";
}

unset(
$o1);

if (
$r1->valid()) {
    echo 
"Object still exists!\n";
    
var_dump($r1->get());
} else {
    echo 
"Object is dead!\n";
}
?>

O exemplo acima irá imprimir:

Object still exists!
object(MyClass)#1 (0) {
}
Destroying object!
Object is dead!

add a note add a note

User Contributed Notes

There are no user contributed notes for this page.
To Top