Multiple 'global' statements allowed in a function?

[sherry]

Hello.

Are multiple 'global' statements allowed in a function?

For example:

A 'global' statement is declared at the top of the function. It contains vars that HAVE to be used under any circumstance and must be declared at the beginning of the function.

Farther into the code and based on 'if/else' conditions, more vars may be needed to be added to the global statement.

Can another (2nd) 'global' statement be added within that function without affecting the 1st OR would an error be generated?

Thanks in advance.

[NogDog]

I'm not aware of any limitations on the number of "global" statements within a function. However, I would recommend you carefully consider the need for using it at all. My experience is that global variables within functions often tend to become a source of hard-to-debug errors as your code grows, functions get re-used in new scripts, etc. You might be better off passing variables by reference in the function declaration in order to get the same effect.

// instead of doing this:
function test1()
{
   global $a, $b;
   $a++;
   $b--;
}
$a = 1;
$b = 2;
test1();
// do this:
function test2(&$var1, &$var2)
{
   $var1++;
   $var2++;
}
$a = 1;
$b = 2;
test2($a, $b);

[sherry]

Thanks for your reply.

The reason for this is, the vars I need to pass to this function are not in the namespace of the calling function. The function is located in a common file that is 'required' by a multitude of files and when that common file is 'included', it has the appropriate vars needed in the namespace (re: user, application params, etc.).

This software already exists and I'm customizing it as little as possible; in this case adding to it vs. changing it.

What you've shown in your reply, I have another place it can be used.

Thanks again.

[NogDog]

Sounds like you know what you're doing then. If you're just reading the values within the function, no big deal; but if it changes them, make sure you put a big, noticeable comment to that effect in the code so you don't forget. 🙂

Just a thought in case it might be applicable: another alternative for any such values if they're read-only would be to define() them as constants, as constants always have a global scope.

[sherry]

Wow...never thought of that! I like that. It's safer. Cool!! 😃

Thanks so much!