Week 2

Question 1

What is a data type?

Answer 1

A type is a set of values and operations that are permitted on the values.

Question 2

What are the two kinds of types?

Answer 2

A value type and a reference type.

Question 3

Whats an example of a value type?

Answer 3

int x = 5

Question 4

What’s an example of a reference type

Answer 4

string str = “hello”

Question 5

Where is the actual data stored for a reference type?

Answer 5

In the heap.

Question 6

Where is the reference stored for a reference type?

Answer 6

In the stack (value types are also found in the stack)

Question 7

What are some examples of a value type?

Answer 7

int, double, long, char, bool, decimal

Question 8

What are some examples of a reference type?

Answer 8

objects, strings, lists (any classes as well)

Question 9

What’s a field?

Answer 9

a field stores data within a class

Question 10

What’s a property?

Answer 10

Looks and acts like a field however it does not allocate memory for data.
ex:
class Demo
{ private int theRealValue; //a field
public int MyValue //a property
{
set{ theRealValue = value; }
get{ return theRealValue; }
}
}

Question 11

What return type do set statements have?

Answer 11

a void return type

Question 12

What return type do get statement have?

Answer 12

returns a value of the type of the property

Question 13

What’s a method?

Answer 13

A block of code thar can be executed (or called).

Question 14

What’s a constructor?

Answer 14

A kind of method, that is used to initialize the state of a class instance.

Question 15

What is an access modifier?

Answer 15

The access modifier optionally specifies what other part of the program can access the member. (ex. public, private)

Question 16

Where can private members be accessed?

Answer 16

Within the class in which they are declared.

Question 17

Where can public members be accessed?

Answer 17

Throughout the entire program.

Question 18

How do you instantiate a string, from a char array called “chars”?

Answer 18

string str = new string(chars);

Question 19

Are strings immutable?

Answer 19

Yes

Question 20

What does the StringBuilder class do?

Answer 20

Helps us produce strings while reducing the number of copies being made. It is mutable.

Question 21

What namespace does the StringBuilder class use?

Answer 21

using System.Text;

Question 22

What symbol is necessary to write an interpolated string.

Answer 22

$

Question 23

OOP supports information hiding by using private fields, what is this called?

Answer 23

Encapsulation

Question 24

What is concept of inheritance?

Answer 24

Types can be derived from other types, a type can be a subtype.

Question 25

What is polymorphism?

Answer 25

The ability of an object to take on many forms.

Question 26

What namespace do lists use?

Answer 26

using System.Collections.Generic;