Question

Is it possible to have a function in PHP which takes 1 or more numbers and returns their sum ?

Answer 1

You can make use of the function func_num_args and func_get_arg as:

function sum() {
        for($i=0,$sum=0;$i<func_num_args();$i++) {
                $sum += func_get_arg($i);
        }
        return $sum;
}

And call the function as:

echo sum(1);       // prints 1
echo sum(1,2);     // prints 3
echo sum(1,2,3);   // prints 6