Merge pull request #3 from guil95/master

Include argument types

src/Percentage.php

@@ -4,44 +4,65 @@
 
 namespace Mattiasgeniar\Percentage;
 
-class Percentage
+final class Percentage
 {
     /**
+     * @param float $a
+     * @param float $b
+     * @return float
+     *
      * What is the percentage increase or decrease from $a to $b ?
      */
-    public static function differenceBetween($a, $b): float
+    public static function differenceBetween(float $a, float $b): float
     {
         return floatval(($b - $a) / $a * 100);
     }
 
     /**
+     * @param float $a
+     * @param float $b
+     * @return float
+     *
      * What is the absolute percentage increase or decrease from $a to $b ?
      */
-    public static function absoluteDifferenceBetween($a, $b): float
+    public static function absoluteDifferenceBetween(float $a, float $b): float
     {
         return floatval(abs(static::differenceBetween($a, $b)));
     }
 
     /**
+     * @param float $a
+     * @param float $b
+     * @return float
+     *
      * How much is $a of $b in percentages?
      */
-    public static function calculate($a, $b): float
+    public static function calculate(float $a, float $b): float
     {
         return floatval($a * 100 / $b);
     }
 
     /**
+     * @param float $percentage
+     * @param float $number
+     * @return float
+     *
      * Get a percentage return from a number.
      */
-    public static function of($percentage, $number): float
+    public static function of(float $percentage, float $number): float
     {
         return floatval($number * ($percentage / 100));
     }
 
     /**
+     * @param float $percentage
+     * @param float $a
+     * @param float $b
+     * @return float
+     *
      * Get the absolute value if you extend range $a to $b with $percentage.
      */
-    public static function extension($percentage, $a, $b): float
+    public static function extension(float $percentage, float $a, float $b): float
     {
         $movement = abs($a - $b);