Bubble sort in php

Also added PHP to book.json

Author: PudottaPommin

CONTRIBUTORS.md

@@ -51,3 +51,5 @@ Gibus Wearing Brony
 Arun Sahadeo
 <br>
 NIFR91
+<br>
+Michal Hanajik

book.json

@@ -120,8 +120,11 @@
         {
           "lang": "crystal",
           "name": "Crystal"
+        },
+        {
+          "lang": "php",
+          "name": "PHP"
         }
-
       ]
     }
   }

contents/bubble_sort/bubble_sort.md

@@ -42,6 +42,8 @@ This means that we need to go through the vector $$\mathcal{O}(n^2)$$ times with
 [import:3-13, lang:"ruby"](code/ruby/bubble.rb)
 {% sample lang="crystal" %}
 [import:1-11, lang:"crystal"](code/crystal/bubble.cr)
+{% sample lang="php" %}
+[import:3-15, lang:"php"](code/php/bubble_sort.php)
 {% endmethod %}
 
 ... And that's it for the simplest bubble sort method.
@@ -89,6 +91,8 @@ Program.cs
 [import, lang:ruby"](code/ruby/bubble.rb)
 {% sample lang="crystal" %}
 [import, lang:"crystal"](code/crystal/bubble.cr)
+{% sample lang="php" %}
+[import, lang:"php"](code/php/bubble_sort.php)
 {% endmethod %}
 
 <script>

contents/bubble_sort/code/php/bubble_sort.php

@@ -0,0 +1,21 @@
+<?php
+
+function bubble_sort(array $arr): array
+{
+  for ($i = 0, $length = count($arr); $i < $length; $i++) {
+    for ($j = 1; $j < $length; $j++) {
+      if ($arr[$j - 1] > $arr[$j]) {
+        $tmp = $arr[$j - 1];
+        $arr[$j - 1] = $arr[$j];
+        $arr[$j] = $tmp;
+      }
+    }
+  }
+  return $arr;
+}
+
+$unsorted = [1, 2, 6, 47, 4, 9, 3, 7, 8, 23, 15];
+$bubble_sorted = bubble_sort($unsorted);
+
+echo sprintf('Unsorted: %s%s', implode(',', $unsorted), PHP_EOL);
+echo sprintf('Sorted: %s%s', implode(',', $bubble_sorted), PHP_EOL);