polymorphism

What is the difference between dynamic and static polymorphism in Java?

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Polymorphism 1. Static binding/Compile-Time binding/Early binding/Method overloading.(in same class) 2. Dynamic binding/Run-Time binding/Late binding/Method overriding.(in different classes) overloading example: class Calculation { void sum(int a,int b){System.out.println(a+b);} void sum(int a,int b,int c){System.out.println(a+b+c);} public static void main(String args[]) { Calculation obj=new Calculation(); obj.sum(10,10,10); // 30 obj.sum(20,20); //40 } } overriding example: class Animal { public void move(){ … Read more

How to call base.base.method()?

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Just want to add this here, since people still return to this question even after many time. Of course it’s bad practice, but it’s still possible (in principle) to do what author wants with: class SpecialDerived : Derived { public override void Say() { Console.WriteLine(“Called from Special Derived.”); var ptr = typeof(Base).GetMethod(“Say”).MethodHandle.GetFunctionPointer(); var baseSay = … Read more

Private virtual method in C++

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Herb Sutter has very nicely explained it here. Guideline #2: Prefer to make virtual functions private. This lets the derived classes override the function to customize the behavior as needed, without further exposing the virtual functions directly by making them callable by derived classes (as would be possible if the functions were just protected). The … Read more

Polymorphism: Why use “List list = new ArrayList” instead of “ArrayList list = new ArrayList”? [duplicate]

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The main reason you’d do this is to decouple your code from a specific implementation of the interface. When you write your code like this: List list = new ArrayList(); the rest of your code only knows that data is of type List, which is preferable because it allows you to switch between different implementations … Read more

Re-raise exception with a different type and message, preserving existing information

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Python 3 introduced exception chaining (as described in PEP 3134). This allows, when raising an exception, to cite an existing exception as the “cause”: try: frobnicate() except KeyError as exc: raise ValueError(“Bad grape”) from exc The caught exception (exc, a KeyError) thereby becomes part of (is the “cause of”) the new exception, a ValueError. The … Read more

What is the main difference between Inheritance and Polymorphism?

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Inheritance is when a ‘class’ derives from an existing ‘class’. So if you have a Person class, then you have a Student class that extends Person, Student inherits all the things that Person has. There are some details around the access modifiers you put on the fields/methods in Person, but that’s the basic idea. For … Read more

Why does an overridden function in the derived class hide other overloads of the base class?

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Judging by the wording of your question (you used the word “hide”), you already know what is going on here. The phenomenon is called “name hiding”. For some reason, every time someone asks a question about why name hiding happens, people who respond either say that this called “name hiding” and explain how it works … Read more

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