Question

for example shuffle(&$array);

is it a bad practice to leave out the & sign when passing argument to functions like this one? Because it’s working without it too…

Answer 1

In PHP 5.3 it is bad, in earlier versions I suppose on some sort of meta way it can help the next person to read the code, but it generally is not the best idea just because it doesn’t really do anything and most people will be confused by its inclusion (why is this person doing that? I don’t get it…). & is used only four times:

• Assigning a variable reference: $a =& $b (a references b)
• parameters: function inc(&$b){$b++;} (b will now increment outside of func)
• returns: function &get_thing(){ static $thing; return $thing; } (You can now modify the static value)
• Iterations: foreach($var as $key=>&$val){$val++;}