Outputting data from a function into a variable

[Helios]

Suppose I have a function, I'll call it output_data().

function output_data($data) {

print("<li>$data</li>\n");

}

I want to read the results of this function into an array, so that

$output = output_data("item1");
$output . = output_data("item2");
$output . = output_data("item3");

will set the value of $output to "<li>item1</li>\n<li>item2</li>\n<li>item3</li>\n".

So my question is, what do I use in the output_data function? Does print() work? I need something like return() that will not end the working of the function.

[LordShryku]

function output_data($data) { 
   $stuff = "<li>".$data."</li>\n";
   return $stuff; 
}

$output = output_data("item1"); 
$output . = output_data("item2"); 
$output . = output_data("item3");

echo $output;