C# Classes / Objects / Inheritance

Question 1

What does overloading constructors mean?

Answer 1

Overloaded constructors enable objects of a class to be conveniently initialized in different ways. To overload constructors, simply provide multiple constructor declarations with different signatures.

Question 2

What is the special use case for the this keyword to prevent code duplication for constructor overloading?

Answer 2

Question 3

What is a common gotcha when dealing with constructors?

Answer 3

Question 4

What is a constructor initializer?

Answer 4

: this(time.Hour, time.Minute, time.Second) { }

This is called a constructor initializer. Enables a class to reuse initialization code provided by a constructor, rather than defining similar code in another constructor.

Question 5

What is the nameof operator?

Answer 5

It’s common to include in an exception’s error message a variable’s or property’s identifier. As of C# 6, you can instead use the nameof operator, which returns a stringrepresentation of the identifier enclosed in parentheses.

Question 6

What is garbage collection and what are destructors?

Answer 6

Question 7

What are readonly Instance variables?

Answer 7

Question 8

When should you use readonly over const?

Answer 8

Question 9

When to use const over readonly?

Answer 9

Question 10

How do you auto implement getter property and readonly?

Answer 10

Question 11

What is the object browser?

Answer 11

Question 12

What is the object initializer syntax look like when there is no perfect constructor for your needs but the instance variables are there?

Answer 12

Question 13

What is operator overloading?

Answer 13

You can create operators that work with objects of your own types — via a process called operator overloading. You can overload most operators!

Question 14

What is a Struct and when should you use one over a class?

Answer 14

Question 15

What would overloading an operator in a stuct look like?

Answer 15

Question 16

What would overloading the - and * operators look like?

Answer 16

Question 17

What can’t you do with a struct?

Answer 17

Question 18

What keyword is used to overload operators?

Answer 18

Question 19

Can you overload an operator method for two different types?

Answer 19

Question 20

What are extension methods?

Answer 20

Question 21

What is inheritance?

Answer 21

Inheritance allows a new class to absorb an existing class’s member. A derived class normally adds its own fields and methods to represent a more specialized group of objects. Inheritance saves time by reusing proven and debugged high-quality software.

Question 22

What is a direct base class?

Answer 22

The direct base class is the base class which the derived class explicitly inherits

Question 23

What is an indirect base class?

Answer 23

An indirect basae class is any class above the direct base class in the class hierarchy. The class hierarchy begins with class object.

Question 24

Which type of relationship represents inheritance?

Answer 24

The is-a relationship

eg. a car “is a” vehicle

a dog “is a” specialized kind of mammal

Question 25

What are the differences between base classes and derived classes?

Answer 25

Base classes are "more general" (mammal) and derived classes are "more specific" (cat)

Question 26

What would a UML diagram of the relationships of the base/derived classes look like?

Answer 26

Question 27

What are some characteristics and uses of base/derived classes?

Answer 27

Question 28

What are protected members?

Answer 28

Question 29

What to use private or protected fields?

Answer 29

Question 30

How to use lambda functions to create methods in a class?

Answer 30

Look at the arrow function syntax.

Question 31

Can you change the access modifier when overriding a method?

Answer 31

Question 32

Best way to create variable that only need to be get?

Answer 32

First initialize the values in the constructor then do a property with get only auto generated;

Question 33

Best way to create and use an instance variable that needs get and protected set?

Answer 33

first create private instance variable, then a property that gets and protected sets.

Question 34

What does DRY mean?

Answer 34

Dont Repeat Yourself

Question 35

What would constructor (passing) look like? \*\*cant remember the name \*\*

Answer 35

Question 36

What do the virtual and abstract keywords do?

Answer 36

Question 37

Where can using protected instance variables cause problems?

Answer 37

Question 38

What is the base. method invocation and when should it be used?

Answer 38

Question 39

How do constructors in derived classes work?

Answer 39

Question 40

What are the main benefits to inheritance?

Answer 40

Question 41

What does the ToString method do?

Answer 41

Question 42

What does the Reference-Equals method do?

Answer 42

Question 43

What does the Memberwide-Clone method do?

Answer 43

Question 44

What does the GetType method do?

Answer 44

Question 45

What does the GetHashCode method do?

Answer 45

Question 46

What does the Finalize method do?

Question 47

What does the Equals method do?

Answer 47