5.1. Caculator

C1: Kéo thả

C2: if - else 

C3: Methods

C4: OOP

C1 :

C2 :

C3 :

C4 :

🔹 CalculatorView.java (View)

🔹 CalculatorController.java (Controller)

🔹 CalculatorModel.java (Model)

🔹 CalculatorApp.java (Main)