PHP unreferencing

test.php

<?php
$a = new stdClass();
$a->prop = 'objA';

$b = new stdClass();
$b->prop = 'objB';

$c = array($a, $b);

echo 'before unsetting'.PHP_EOL;
array_map(function($obj) {
    echo $obj->prop.PHP_EOL;
}, $c);

unset($b);

echo 'after unsetting'.PHP_EOL;

array_map(function($obj) {
    echo $obj->prop.PHP_EOL;
}, $c);


// Output 

clemherreman@macclem ~ $ php test.php 
before unsetting
objA
objB
after unsetting
objA
objB // ObjB is still there because unset doesn't destroy an object, only a reference (here $b)