PHP: pass a variable to a function, do something to the variable, return it back

Question

Assuming the following code:

Answer 1

You either have to assign the return value of the doStuff calls back to the local $rowCount variable:

$rowCount = 1;
echo $rowCount.' and ';
$rowCount = doStuff($rowCount);
$rowCount = doStuff($rowCount);
$rowCount = doStuff($rowCount);

Or you pass the variable as a reference by putting a & in front of the formal parameter $rowCount:

function doStuff(&$rowCount) {
    $rowCount++;
    echo $rowCount.' and ';
    return $rowCount;
}

Now the formal parameter $rowCount inside the function doStuff refers to the same value as the variable that is passed to doStuff in the function call.