comments

T5Q2-B-FromSol1/T5Q2-B-FromSol1.iml

@@ -5,7 +5,7 @@
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
     </content>
-    <orderEntry type="jdk" jdkName="openjdk-22" jdkType="JavaSDK" />
+    <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
 </module>

T5Q2-B-FromSol2/T5Q2-B-FromSol2.iml

@@ -5,7 +5,7 @@
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
     </content>
-    <orderEntry type="jdk" jdkName="openjdk-22" jdkType="JavaSDK" />
+    <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
 </module>

T5Q2-C/T5Q2-C.iml

@@ -5,7 +5,7 @@
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
     </content>
-    <orderEntry type="jdk" jdkName="openjdk-22" jdkType="JavaSDK" />
+    <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
 </module>

T5Q2-C/src/Main.java

@@ -14,12 +14,18 @@ public class Main {
 //        a.print(12, "there"); // Ok
 //        a.print(88); // Compilation error
 
-        // IV
-//        ClassA a = new ClassC(); // Ok
-//        ClassG g = new (ClassG)a; // Syntax error
+        // IV - We do not have access to a print(String) from the ref C, even though it was downcasted to the obj G
+        // ObjectType <- ReferenceType
+        // Compiler always keep tracking of ObjectType
+        // While only during Runtime that we will check and execute the ReferenceType
+//        ClassA a = new ClassC(); // Ok -> Upcast A<-C
+//        ClassG g = (ClassG)a; // Ok -> Downcast G<-(A<-C)
 //        g.print("hello"); // RunTime error: trick
+        // Upcast is prone to Compiler error
+        // Downcast is prone to Runtime error
 
-        // V
+
+        // V - We lost track of the print(string, string) in C become it become a A first
 //        ClassA a = new ClassC(); // ok
 //        ClassG g = (ClassG)a; // ok
 //        g.print("hello", "there"); // Runtime error: trick