PHP: Why will the code in the if block run?

Question

$a = 2;
$b = „Hello world“;

if($a && $b) {
//the following code will run
}

Answer 1

Because everything diffrent from zero will be interpreted as true!
Or any non Empty Objects or Strings/Arrays...

I know this from C where it is the same.

Answer 2

This may have to do with the bitwise representation of a empty string.

Answer 3

empty strings will also be interpreted as true
$c = „“;