Question

I was reading an article about Data Encapsulation in PHP, and the author explained in such a way that it made me to wonder if this is really possible? here is what he said.

The primary purpose of encapsulation
(scope) is to ensure that you write
code that can’t be broken. This
applies to scope in general, so let me
use a simpler example of a local
variable inside a function:

function xyz ($x) {
  $y = 1;
  while ($y <= 10) {
    $array[] = $y * $x;
    $y++;
  }
  return $array;
}

The purpose of this function is to
pass a number and return an array. The
example code is pretty basic. In order
for function xyz() to be dependable,
you need to be guaranteed that it does
the exact same thing every time. So
what if someone had the ability to
from the outside change that initial
value of $y or $array? Or even $x? If
you were able to do that from outside
of the function, you could no longer
guarantee what that function is
returning.

Now this made me wonder can i really change the value of local variable sitting inside the function without using any argument as demonstrated above ?? if it is possible how do i do it?

thank you..

Answer 1

For this example you wouldn’t be able to change any of the variables, because they’re all declared inside of the function.

But if you had a class with a public class variable, you could change that outside of the class if you wanted to. (That’s bad form and might screw a lot of things up, though.)