PHP SplObjectStorage offsetUnset() Function

<?php

// Create an empty SplObjectStorage
$str = new SplObjectStorage;
$obj = new StdClass;

// Set offset $obj to $str 
$str->attach($obj, "GeeksforGeeks");

// Print Result before
var_dump(count($str));

// Unset object from storage
$str->offsetUnset($obj);

// Print Result after
var_dump(count($str));

?>

<?php

// Create an Empty SplObjectStorage
$str = new SplObjectStorage();
 
$obj1 = new StdClass;
$obj2 = new StdClass;
$obj3 = new StdClass;
$obj4 = new StdClass;
 
$str->attach($obj1, "GeeksforGeeks");
$str->attach($obj2, "GFG");
$str->attach($obj3);
$str->attach($obj4, "DSA");
 
// Print Result before
var_dump(count($str));

// Unset object from storage
$str->offsetUnset($obj1);
$str->offsetUnset($obj2);
$str->offsetUnset($obj3);
$str->offsetUnset($obj4);


// Print Result after
var_dump(count($str));
?>