Unit 1: Introduction to C# Object Programming

Question 1

Object Oriented Programming definition.

Answer 1

OOP can be defined as a programming model which is based upon the concept of objects

Question 2

Example OF Object Oriented Programming

Answer 2

Examples of an object, can range from physical entities: such as human beings who are described by properties( attributes)
like name and address, to small computer programs such as widgets.

Question 3

What are classes?

Answer 3

Classes are user defined data types: that act as the blueprint for individual objects, attributes and methods.

Question 4

What are Objects?

Answer 4

Objects are instances of a class created which specifically Define the data.

Question 5

What are Methods?

Answer 5

Methods are functions that are defined inside a class that describe the behaviors of an object.

Each method contains in class definitions stored with a reference to an instance object.

Question 6

Some cartoons contained in an object are called…..?

Answer 6

instance methods

Question 7

What are Attributes?

Answer 7

Attributes represent the state of an object and are defined in the class template.

Question 8

objects will have data stored in the……?

Answer 8

attribute field, class attributes belong to the class itself .

Question 9

Methods control the…….

Answer 9

Movements or actions of the Object.

Question 10

What is Abstraction?

Answer 10

Abstraction is a process where you show only” relevant” data and “ hide” unnecessary details of an object from the user.

Question 11

What is Encapsulation?

Answer 11

Encapsulation is defined as a practice that bind data with the code that manipulates it and keeps the data and the code safe from external inheritance.

Question 12

What is Inheritance?

Answer 12

Inheritance is the mechanism by which an object acquires the same( or all) properties of another object.

Question 13

What is Polymorphism ?

Answer 13

Polymorphism is Ability to process objects differently based on their data type.

In other words objects can have the same name for two methods but their implementation may differ.

Question 14

A visual representation Encapsulation is….?

Answer 14

data security

Question 15

A visual representation Inheritance is….?

Answer 15

code reusability

Question 16

A visual representation polymorphism is….?

Answer 16

code reusability

Question 17

A visual representation abstraction is….?

Answer 17

hidden complexity

Question 18

the object is found within…?

Answer 18

the class

Question 19

You can use this features to withdraw the money but you never will know what exact actions are operation take place internally in the machine like after card swipe the machine check whether the card is valid or not then the pin will be verified if it is correct then only we can withdraw the money.
WHICH CONCEPT IS USED?

Answer 19

Abstraction

Question 20

a watch you check the time many times in a day but you never need to know what the internal mechanisms of the watch is
WHICH CONCEPT IS USED?.

Answer 20

Abstraction

Question 21

A pet class and a person class
would have a name attribute we can call within getter/setter functions that assign the value

What do you think we should use so that the code knows when the function that is being called and the variable that you are trying to assign?

Answer 21

Using encapsulation comes into provide a layer

Question 22

When you are in a classroom , you act like a student when you are in a store, you act like a customer and when you’re at home you act like a daughter or son.

Answer 22

The answer is Polyomorphism since it’s different behaviors but one person

Question 23

A child inherits the traits of his/her appearance

Answer 23

Answer: inheritance

Question 24

List 3 Benefits of Object-Oriented programming

Answer 24

a. Reuse of Code
b. Reduction of errors
C. Faster application development

Question 25

Encapsulation enables objects to be self-contained, making troubleshooting and collaborative development easier.

Answer 25

Modularity

Question 26

The code can be reused through inheritance, a team does not have the write the same code multiple times.

Answer 26

Reusability

Question 27

Programmers can construct new programs quicker through the use of multiple libraries and reusable code.

Answer 27

Productivity

Question 28

Easily Upgradable and Scalable

Answer 28

Programmers can implement systems functionalities independently

Question 29

Descriptions of external systems are simple, due to message passing techniques that are used for objects communication.

Answer 29

Interface Descriptions

Question 30

Through using encapsulation and abstraction, complex code Is hidden, software maintenance is easier and the internet, Protocols are protected.

Answer 30

Security

Question 31

Polymorphism enables a single Function to adapt to the class it is placed in. different objects can also pass through the same interface.

Answer 31

Flexibility

Question 32

What are Classes Again?

Answer 32

Classes are user-defined data types that represent the state and behavior of an object.

Question 33

What is referred to as the state and behavior?

Answer 33

The state represents the properties, and behavior is the action that objects can perform.

Question 34

Classes can be declared using the following access specifiers that limit the accessibility of classes to other classes.
What are they?

Answer 34

1.Public
Public class Accounts {

							    }   2.Private  3.Protected  4.Internal  5.protected internal

Question 35

List 4 Points about classes:

Answer 35

1.Classes are reference types that hold the object created dynamically in a heat

2.All classes have a base type of System.object

3.The default access modifier of a class is internal

4.The default access modifier of methods and variables is private
directly inside the namespace, declaration of private classes are not alone

Question 36

If there is a need for command line arguments the user must specify the command line arguments in the Main method.
USING………

Answer 36

Using System;
Class GFG{
//Main method
Protected static void Main()
}
Console.WriteLine(“Main method”);

Question 37

Public, private, protected, internal and protected internal access modifiers can b e used with the

Answer 37

Main() method.

Question 38

The Main method can also have integer return type

Answer 38

Returning an integer value from Main()

Question 39

Methods cause the program to obtain…..

Answer 39

status information.

Question 40

The value which is returned from the Main() method is treated as the ……

Answer 40

exit code for the process.

Question 41

Return type Example

Answer 41

Using System;

Class GFG{
//Main method
Static int Main()
{

	Console.WriteLine(“Main method”);

		//for successful execution of code
		Return 0;
	}

Question 42

What does namespace do?

A namespace is a declarative region that provides a scope to the identifiers (the names of types, functions, variables, etc) inside it.

Answer 42

Namespaces are used to organize code into logical groups and to prevent name collisions that can occur especially when your code base includes multiple libraries.

Question 43

Using System;

Class GFG{
//Main method
Static int Main()
{

	Console.WeiteLine(“Main method”);

		//for successful execution of code
		Return 0;
	} What does namespace do? 

Using System; (used to define or direct)

namespace MyNamespace
{
public class SampleClass
{
public static void myMethod()
{
Console.WriteLine(“Creating my namespace”);
}
}
}

Namespace MyProgram
{
public class MyClass
{

	public static void Main()
	{
		MyNamespace.SampleClass.myMethod();
	}
} }

Answer 43

In the program the namespace is created with MyNamespace and the members are accessed from the Main() method inside MyClass.
The dot(.) operator is used to access the member of the namespace.
In the Main() method, myMethod() method is called using the dot(.) operator.

Question 44

C# Output??

Answer 44

Console.WriteLine(“Hello World!”);

Question 45

C# User Input??

Answer 45

string userName = Console.ReadLine();

Console.WriteLine(“Enter your age:”);
int age = Console.ReadLine();
Console.WriteLine(“Your age is: “ + age);

Question 46

readline(0 returns a string so if you want it to get something else from the user an int for example you have to convert it
How do you convert user input to a number.

Answer 46

Int myNum = Int32.Parse(console.Readline());

Question 47

ToBoolean()

Answer 47

Converts a type to a boolean value

Question 48

ToChar()

Answer 48

Converts a type char type

Question 49

ToDouble()

Answer 49

Converts a type to a double type

Question 50

ToInt16()

Answer 50

Converts a type to a 16 bit type

Question 51

ToString()

Answer 51

Converts a type to a string