public function execute($operatorName)
{
if ($operatorName == "+") {
$addobject = new Add();
$addobject->execute($this->values);
//$this->add();
} else {
if ($operatorName == "-") {
$subtractobject = new Subtract();
$subtractobject->execute($this->values);
//$this->subtract ();
} else {
if ($operatorName == "!") {
$factorialobject = new Factorial();
$factorialobject->execute($this->values);
//$this->factorial ();
} else {
try {
throw new NoSuchOperator('No such operator!');
} catch (NoSuchOperator $e) {
echo 'Caught exception: ' . $e->getMessage();
}
}
}
}
}
<?php
class Factorial
{
private $input;
public function __construct($input)
{
$this->input = $input;
}
public function execute()
{
$answer = 1;
$x = 1;
while ($x <= $this->input) {
$answer = $answer * $x;
$x = $x + 1;
}
return $answer;
}
}
$f = new Factorial(10);
$result = $f->execute();