When passing arguments to functions, the convention is to pass by value if the function is not supposed to change the value of that argument. We pass &byref only when the function is going to modify that variable.
On the other hand, we do know that when passing by reference, PHP works with a pointer, rather than duplicating a copy of the variable as in the case with passing by value.
This brings up a question in my mind, shouldn’t it we pass certain variables to our functions by reference from time to time for speed and efficiency purposes – even though we need them not modified.
Without getting crazy with the idea amd totally abuse it, I’d like to put a frame of reference as to which variables or what kind of variables I’m talking about here.
They are mainly $dbh ( database handles ) and very large variables. to tell you the truth, just the $dbh’s! really.
In your opinion, do you think this is a good practice or do you find it as one that should never be practiced.
Let’s bring this matter down to a code snippet and comment off of that.
//assume $dbh is the database_handle for a mysql connection
for ($userID = 1; $userID <= 1000; $userID++) {
display_name ($dbh,"users",$userID)// outputs the name of the passed userid
}
here, should the display_name function take the $dbh by ref or by value?
PHP uses copy-on-write, which esentially means as long as the variable is not modified, passing it by value has the same effect as passing it by reference. That is to say, there will be no performance gain by using references in the scenario you describe (in fact, some report references can be slower)