PHP and 'out' arg used in a function

rsassine

dear PHPers,
I have a function that returns true or false, but I want to also set one of it's argument to something that I can use later on outside of the function. Example

function myFunc ($a, $b) {
$b = "ABC"; / 'b' is the out /
return $a + $a;
}

/ main /
$d = myFunc (2, $x);
echo "d = $d. x = $x";

Output: "d = 4. x = "

The problem is 'main' does not know what '$x' is. What am I doing wrong?

Raymond

Anon

Yes, you have to tell the function you want to pass this parameter by REFERENCE, as opossed to VALUE passing.

When you pass by value (like in your func), the program makes a copy of the data, process it inside the function and, unless you tell the func to return that data, it doesn't.

Modify your func declaration like this:

function MyFunc($a,&$b){

$b = 3;

}

Then use this:

$a=0;
$b=0;

MyFunc($a,$b);

echo "a value is -->".$a;
echo "b value is -->".$b;

This way, you pass the argument and it gets modified inside the function. If you ever wondered what pointers are, this is a NOT SO GOOD example. But they are used to access the real variable, instead of just the value of it.

Hope this helps

fLIPIS

rsassine

Thanks a lot.
It worked as you've suggested. I did look for help on this and I could NOT find it.

Anything I can help you with?

Raymond

flipis

rsassine wrote:

Thanks a lot.
It worked as you've suggested. I did look for help on this and I could NOT find it.

Really? Well, http://www.php.net has a small feature that might be <B>VERY USEFUL</B> to you, as it is to me on my daily job as a PHP programmer. If you put in the URL the name of the function or feture you want to see the reference about, the site redirects you to that function. Try it:

http://www.php.net/oop (OOP reference)
http://www.php.net/echo (echo() function reference)

So, whenever i have a doubt, insted of going to the book, i simply type this and ta-da! works.

Anything I can help you with?

I made a post in this forum. Read it and maybe you can gimme a hand. It's a very <B>WEIRD</B> thing, anyway. Probably one of my crazy ideas again :-)

Raymond

fLIPIS