🐛 FIX: type errors

Signed-off-by: Jonas Sulzer <jonas@violoncello.ch>

src/Ex_04/Typage.java

@@ -9,15 +9,16 @@ class Typage {
         a[3] = new C(4, 2);
         a[4] = new D();
         int somme = 0;
+        System.out.println(a[1].getClass());
 
         for (int i = 0; i < a.length; i++) {
             if (a[i] instanceof D) {
                 System.out.println(((D) a[i]).d);
             } else {
                 if (a[i] instanceof B) {
-                    somme = somme + ma(a[i]);
+                    somme = somme + ma((B) a[i]); // otherwise a[i] isn't necessarily of type B required by ma()
                     if (a[i] instanceof C) {
-                        C c = a[i];
+                        C c = (C) a[i]; // otherwise a[i] isn't necessarily of type C required by mc()
                         c.mc();
                     }
                 }