<?php
class calc {
private $state;
public function __construct()
{
$this->state = 0;
}
public function add($number)
{
$this->state += $number;
return $this;
}
public function mult($number)
{
$this->state = $this->state * $number;
return $this;
}
public function echo()
{
echo $this->state;
return $this;
}
}
(new calc)->add(3)->add(7)->mult(3)->echo();