What are the three essential ingredients for having a polymorphic method call?

With suitable example, clearly explain the difference between a default constructor and a parameterized constructor

In C#, how would you write (2) programmer defined methods as described below:   Method #1 (GreetingGeneric) — a type void programmer defined method does not require any parameters. It should output a generic greeting line for a letter. For example: "Dear Customer", "Dear Student", etc. Method #2 (GradeMessage) — a type void programmer defined method that has (3) parameters; (string, string, double) for (name, assignment, and grade) and should output the passed parameters in sentence format: GradeMessage("Jimmy", "Midterm Exam", 79.5) would output: Jimmy took the Midterm Exam and got 79.5 points.   The Main() method for this program should: call Method #1 to output the generic greeting ask the user to enter a name, assignment, and grade and pass them to Method #2 for output. Input should only be done in the Main() method and output in the programmer-defined methods.

Describe the concept of the "Liskov Substitution Principle" in the context of method overriding. Why is it important, and how does it ensure the proper behavior of derived classes?

Use java programming properties to write all the necessary classes and/or interfaces for a solution to the problem. Focus on class structure and interaction. You may implement your solution however you wish, but you will be graded on the appropriateness of your solution to the requirements. Note the use of capitalization and parentheses for clarification. You may use whatever constructors or additional methods you wish. Define a structure that can represent Animals. Animals have two behaviors; they can speak() and they can move(). By default, when an animal moves, the text ”This animal moves forward” is displayed. By default, when an animal speaks, the text ”This animal speaks” is displayed. A general Animal should not be able to be instantiated. Define two classes, Goose and Lynx, that are Animals. Both Goose and Lynx behave such that where “Animals” is displayed in speak() or move(), “goose” or “lynx” is displayed by the appropriate classes. Finally, any instance of Goose can fly(),…

How do you mean to use the word "constructors" in this context? For the life of me, I can't figure out what the point of Constructors is.

You need to perform following things to demonstrate the concept of abstract class. Step 1: Create the abstract class that has following methods. • Calculate the area of circle(Abstract method) • Calculate the area of triangle(Abstract method) • Calculate the area of rectangle(Method with implementation) Step 2: Create another class that extends above class and provide implementation of abstract methods. Step 3: Create the main method inside above class and display output of area of circle, area of triangle and area of rectangle. You need to submit the following things: • Java program with both the classes An output screenshot created using Microsoft Word

Ruby-related coding: Need help in resolving the red-selected code parts of my practice problem, primarily dealing with case-sentitive, loops, and if-else statements. The ", :pending => true" needs to be removed, used for checking purposes. (Picture reference provided)     Hangperson_game.rb class HangpersonGame# add the necessary class methods, attributes, etc. here# to make the tests in spec/hangperson_game_spec.rb pass.# Get a word from remote "random word" service# def initialize()# enddef initialize(word)@word = word@guesses = ""@wrong_guesses = ""enddef wordreturn @wordenddef guessesreturn @guessesenddef wrong_guessesreturn @wrong_guessesenddef guess(letter)if @word.include?(letter)@guesses += letterreturn true else@wrong_guesses += letterendenddef word_with_guessespartial_matches = ""@word.each_char do |w|partial_matches += "-"endreturn partial_matchesenddef check_win_or_loseif word_with_guesses.downcase == @word.downcasereturn :winelsif @wrong_guesses.length >= 7return…

In java, can a polymorphic reference invoke a method that is only declared at the object's class level? If "yes", explain how.

Programing in c++