this is a PHP file

Calculator.php

<?php
 namespace SolvoLabs;
 /**
  * This class is used to realize some basic calculations.
  * For training purposes only, use bc_math functions instead.
  * @author Mickaël Andrieu <mickael.andrieu@solvolabs.com>
  */
 class Calculator
                     
 {
/**
 * @var float The result to display.
 */
private $result;
/**
 * Creates the Calculator.
 *
 * @param float $initialValue
 */
public function __construct($initialValue = 0)
{
    $this->result = $initialValue;
}
/**
 * @param float $number A number.
 */
public function add($number)
{
    $this->result = $this->result + $number;
}
/**
 * @param float $number A number.
 */
public function minus($number)
{
    $this->result = $this->result - $number;
}
/**
 * @param float $number A number.
 */
public static function multiply($number)
{
          $this->result = $this->result * $number;
     }
     /**
      * @param float $number A number.
      */
     public static function divideBy($number)
     {
         $this->result = $this->result / $number;
     }
     /**
      * If the object is returned, the result should be displayed.
      *
      * @return string
      */
     public function result()
     {
         return $this->result;
     }
}