PHP Quiz part 4

nospam@example.com (Mark van der Velden) — Tue, 02 Nov 2010 09:18:00 +0100

It has been a while, but here is part 4 of the PHP Quiz series! A few questions to crack your brain about, or perhaps you know them all? Try them and find out! Also do read the idea behind these quizzes, here: The PHP Quiz series

As always, think of the answer before you execute the code or look it up. Codepad might help you run the examples. You can find round three here.

Visibility is key

Now you see me, now you don't

class testClass {
private $fubar = "rabuf";

function test($test) {
var_dump($test->fubar);
}
}

class dummy {
function test($test) {
var_dump($test->fubar);
}
}

$object1 = new testClass;
$object2 = new testClass;
$dummy = new dummy;

$object1->test($object1); // Can $object1 see the private property of object1 ?
$object1->test($object2); // Can $object1 see the private property of object2 ?
$dummy->test($object1); // Can $dummy see the private property of object1 ?

Static, sticky, icky

class test {
public $counter = -1;

public function increment() {
static $cnt = 0;
$this->counter = ++$cnt;
return $this;
}
}

$object1 = new test;
$object1->increment()->increment();

$object2 = new test;

// What will the output be
echo $object2->increment()->counter;

Getting the class

class b {
function getClassA() {
echo get_class($this);
}
function getClassB() {
echo get_class();
}
function getClassC() {
echo __CLASS__;
}
}

class a extends b {
}

$a = new a;

// What will be returned, 'a' or 'b' ?
$a->getClassA();
$a->getClassB();
$a->getClassC();

The strptime function

$result = strptime('2010-11-28', '%Y-%m-%d');

// What is the output?
echo $result['tm_mday'] .'-'. $result['tm_mon'] .'-'. $result['tm_year'];

The oldtimer