General Coding

Question 1

The STACK is…..

Answer 1

The stack is the block of memory for storing local variables

Question 2

The HEAP is…

Answer 2

The heap is the block of memory in which OBJECTS reside

Question 3

What does REST stand for?

Answer 3

Representational State Transfer

Question 4

How do you run a Psake command from the powershell?

Answer 4

.\packages\psake.4.3.2\tools\psake.ps1 [Command] eg .\packages\psake.4.3.2\tools\psake.p21 RebuildDatabase

Question 5

What does IIS stand for?

Answer 5

Internet Information Services

Question 6

What is the S in SOLID?

Answer 6

Single Responsibility

Question 7

What is the O in SOLID?

Answer 7

Open / Close Principle

Question 8

What is UPCASTING?

Answer 8

Creating a BASE class reference from a SUBCLASS reference

eg

Cow myCow = new Cow();

Animal animal = cow; //Upcast

//**animal can only use the methods/properties available to Animal but would take anything across from myCow**//

Question 9

What is DOWNCASTING?

Answer 9

Creating a SUBCLASS reference from a BASE class reference

eg

Animal myAnimal = new Animal();

Cow myCow = (Cow) myAnimal;

Question 10

What does the ‘as’ operator do?

Answer 10

It performs a DOWNCAST but will return null if the downcast fails

eg

Animal myAnimal = new Animal();

Cow myCow = myAnimal as Cow;

this can be followed with an !=null check to confirm the type

Question 11

What does the ‘is’ operator do?

Answer 11

It checks whether an object is of a certain type

eg

if (myAnimal is Cow)

{……}

/**Cow would be a type eg Cow myCow = new Cow(); **/

Question 12

Is GOLD PLATING a GOOD thing or a BAD thing? Why?

Answer 12

It’s viewed as a BAD thing as it represents work / development that was not requested and is therefore wasteful

Question 13

What is the difference between CONST and READ ONLY?

Answer 13

1. CONST must be declared and initialised on compile, READ ONLY can be initialised during the run time, but once the value has been set it can’t be changed

So within an object, you can have different values set for each instance of the object, but any CONST values would be the same across them all.

NB: Both are static

Question 14

What are the differences between Abstracation and Encapsulation?

Answer 14

Abstraction:

1. Abstraction is a concept of hiding mechanism.
2. Only showing those parts which are necessary.
3. It is a thought process used in design level.

Encapsulation:

1. Encapsulation is the implementation of that concept.
2. Hiding complexity.
3. Here it is the actual process of hiding the ‘mechanics’ of the class.

Question 15

How do you convert the following the following method so that the CheckUserName method is run to asynchronously?

private void Login(name)

{

if (CheckUserName(name))

{

MessageBox.Show(“Name Ok”);

};

}

Answer 15

private async Task LoginAsync(name)

{

var result = await Task.Run(() => CheckUserName(name));

if (result)

{

MessageBox.Show(“Name Ok”);

}

}

Question 16

Convert the following task to ASYNC:

private bool IsValidUser(name)

{

if(IsInTheDatabase(name))

{

return true;

}

return false;

}

Answer 16

private async Task IsValidUser(name)

{

var check = await IsInTheDatabase(name);

return check.result;

}

Question 17

Convert the following to async:

public ActionResult Index()

{

using (var db = new AriaDBContext())

{

var query = db.GetAllUsers();

return View(“Index”, query);

}

}

Answer 17

public async Task Index()

{

using (var db = new AriaDBContext())

{

var query = await db.GetAllUsers();

return View(“Index”, query.result);

}

}

Question 18

In Visual Studio, how can you quickly see the list of parameters expected within a method call?

Answer 18

Ctrl + Space

Question 19

What is Abstraction?

Answer 19

It’s an OOP principle where we show only necessary things to the consumer.

Question 20

If you have a static class, when do you need to instantiate it and how many instances can you instantiate?

Answer 20

This is a trick question, you don’t need to instantiate a static class, it’s always available. However because of this you can only ever have one ‘instance’ of it available. The contents of which remains static across the application.

However, it’s worth noting that although the variables and methods within the static object don’t change, it can still return different values (including different objects and instances of objects) from it’s methods

Question 21

Lazy Loading

Answer 21

Lazy Loading :- This is a creational design pattern where we load objects only when we need it. The opposite of Lazy loading is eager loading.