{ "cells": [ { "cell_type": "markdown", "id": "c7c45369", "metadata": {}, "source": [ "# Chapter Review\n", "\n", "- Follow the lab assignment format to prepare this assignment.\n", "- Create a project folder called `Ch10Classes` to include the code for this\n", " project.\n", "- Question 6~10 require code and execution screenshots when applicable.\n", "\n", "01. What is the keyword used to create an instance of a class?\n", "\n", "02. Can you create an object from a class resides in another file?\n", "\n", "03. What is the purpose of a constructor?\n", "\n", "04. Describe the process of implementing inheritance in polymorphism in steps.\n", "\n", "05. If you want to use an instance variable (field) in a method, should you declare\n", " that instance variable in the method? Why?\n", "\n", "06. How do you create an instance of the following class?\n", "\n" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ " class DoMath\n", " {\n", " public int Sum(int num1, int num2)\n", " {\n", " var total = num1 + num2;\n", " return total;\n", " }\n", " }\n" ], "id": "4bb3baed" }, { "cell_type": "markdown", "id": "8eead56b", "metadata": {}, "source": [ "\n", "07. How do you use the following class to use the Sum method for summing up two integers? Prepare\n", " your code in your Program.cs Main method.\n", "\n" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ " static class SomeMath\n", " {\n", " public static int Sum(int a, int b)\n", " {\n", " return a + b;\n", " }\n", " }\n" ], "id": "568c0948" }, { "cell_type": "markdown", "id": "dfc30ccc", "metadata": {}, "source": [ "\n", "08. Define a `Math` class, when **instantiated**, offer the functionality of two\n", " summing methods with the same name Sum that would take 2 and 3 arguments,\n", " respectively, and sum them up and return the results.\n", "\n", "09. Change the preceding code to allow the passing of an unspecified number of integer arguments\n", " (see, e.g., ).\n", " Save the file in the project folder,call it SumManyArgs.cs and use SumManyArgs as the class name.\n", "\n", "10. Does the following code define a public or private class? Add an access modifier without\n", " changing the existing accessibility level. Show your changed code and explain why.\n", "\n" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ " class Customer\n", " {\n", " // Fields, properties, methods and events go here...\n", " }\n" ], "id": "e9fac46b" }, { "cell_type": "markdown", "id": "59460f4f", "metadata": {}, "source": [ "\n", "% #. What does the ``this`` keyword do in the context of this chapter?\n", "\n", "% #. If we want users to be able to see the value of a private instance variable\n", "\n", "% from outside of the class, how do we do it?\n", "\n", "% #. What is the general name of the category of public methods whose sole purpose\n", "\n", "% is to set a part of instance state to a new specified value?\n", "\n", "% #. If you do not explicitly assign a value to an instance variable in a\n", "\n", "% constructor, does the instance variable have a value?\n", "\n", "% #. What is the general name of the category of methods that return\n", "\n", "% instance state values?\n", "\n", "% #. Instance variables are usually visible from inside instance methods for\n", "\n", "% the class. What is the exception? In the exceptional case, what is\n", "\n", "% the workaround to allow access to the instance variable?\n", "\n", "% #. Sometimes you need to refer explicitly to the current object. How\n", "\n", "% do you do it?\n", "\n", "% #. What is the return type for a setter method?\n", "\n", "% #. If a class has one or more setter methods, is the object type\n", "\n", "% immutable?\n", "\n", "% #. Where in a class are instance variables declared?\n", "\n", "% #. For most instance variables, what is the modifier used that does not\n", "\n", "% appear at the beginning of a local variable declaration?\n", "\n", "% #. What is the lifetime of an instance variable:\n", "\n", "% When does it come into existence, and how long does it last?\n", "\n", "% #. Why do we generally make an instance variable ``private``?\n", "\n", "% #. In what code can an instance variable be seen and used?\n", "\n", "% #. Must instance variables and methods always be preceded by\n", "\n", "% an explicit object reference and ``.``?\n", "\n", "% #. Can we refer to an instance variable in a part of the code\n", "\n", "% where there is no current object?\n", "\n", "% #. In what kind of method in a class definition are instance variables never\n", "\n", "% accessible?\n", "\n", "% #. A method with what signature allows you to control how the string\n", "\n", "% concatenation operate (``+``) generates a string from the object?\n", "\n", "% #. If you write an override the ``ToString`` method in a class, should the method\n", "\n", "% print the string? If not, what should it do with the resulting string?\n", "\n", "% #. Can aliased objects cause problems when created for an immutable object?\n", "\n", "% Mutable object?\n", "\n", "% #. In a class with instance methods you can always design the class so variables\n", "\n", "% are instance variables and not local variables. When should you\n", "\n", "% use local variables instead?\n", "\n", "% #. If an instance method has a formal parameter of the same type as the\n", "\n", "% class being defined,\n", "\n", "% can you refer to a private instance variable in the parameter object?\n", "\n", "% May you change it?\n", "\n", "% How do you distinguish an instance variable for the current object from the\n", "\n", "% corresponding instance variable for the parameter object?" ] } ], "metadata": { "jupytext": { "cell_metadata_filter": "-all", "main_language": "python", "notebook_metadata_filter": "-all" }, "kernelspec": { "display_name": ".NET (C#)", "language": "C#", "name": ".net-csharp" }, "language_info": { "name": "csharp" } }, "nbformat": 4, "nbformat_minor": 5 }