Code smell.

classes/Battles/UserProfile.php

@@ -47,10 +47,10 @@ class UserProfile
 
 
 
-    public function changePassword($old_password, $new_password)
+    public function changePassword($oldPassword, $newPassword)
     {
-        if (password_verify($old_password, $this->pass)) {
-            $this->pass = password_hash($new_password, PASSWORD_DEFAULT);
+        if (password_verify($oldPassword, $this->pass)) {
+            $this->pass = password_hash($newPassword, PASSWORD_DEFAULT);
         } else {
             $this->status .= 'Неверный пароль!';
         }
@@ -160,4 +160,4 @@ class UserProfile
         return 'Успешно!';
     }
 
-}
+}