Do I need to use the ampersand in PHP 5.5.X and above anymore?

Question

I\'m getting mixed signals all over the place.

Do I use the ampersand to pass variables by reference or not?

The following link seems to tell me that it is depre

Answer 1

No, it is not.

• Objects are always automatically passed as references (info! see below for additional important information!)

• Declaring paramters as references must happen at the function definition:

  function test(&$var) {}
  

  Not at the time of calling it:

  // wrong
  $var = '123';
  test(&$var);
  

---

If you pass an object as usual, you can alter the object's state (properties).
Assume that $obj is an instance of the class TestClass which contains a member variable called hello (click here for a full sample at Ideone.com):

function modify($obj) { $obj->hello = 'world (modified)!'; }

$obj->hello = 'world';
modify($obj);
var_dump($obj->hello);  // outputs "world (modified!)"

This should be self-explanatory. Now, using the same code but assigning another value to $obj instead modifying the object's state results in no modification (→ Ideone.com):

function modify($obj) { $obj = 42; }
// ...
var_dump($obj->hello);  // outputs "world"

Only accepting the parameter explicitly as a reference gives us the ability to completely change the variable's contents (→ Ideone.com):

function modify(&$obj) { $obj = 42; }
// ...
var_dump($obj);         // outputs "42"