70-483

Question 1

Usage of the volatile keyword

Answer 1

Can be used to indicate that operations involving a particular variable will not be optimized, and the value will be fetched from the copy in memory, rather than being cached in the processor

Question 2

What does the Parallel.Invoke method do?

Answer 2

Accepts a number of Action delegates and creates a Task for each of them. The method can start a large number of tasks at once

Question 3

When does the Parllel.Invoke returns?

Answer 3

When all of the tasks have completed

Question 4

Do we have control over the order in which tasks are started when using Parallel.Invoke method?

Answer 4

No, we don’t have control over the order nor the processor assigned.

Question 5

How do we use the Parallel.ForEach method?

Answer 5

In the first parameter we add a IEnumerable collection to iterate over. The second parameter provides an Action method to perform on each item in the list.

Question 6

What’s the difference between struct and class?

Answer 6

1. It is not possible to have a parameterless constructor within the structure.
2. The struct is used to create value types, the class is used to create reference types.
3. The constructor of a structure must initialize all the data members in the structure.

Question 7

What’s the signature of a method?

Answer 7

The signature defines the type and number of parameters that the method will accept

Question 8

What is the sequence that is performed when a new instance of a class is created?

Answer 8

1. The code that implements the class is loaded into memory, if it is not already present.
2. Any static members of the class are initialized(if is the first time that the class has been referenced) and the static constructor is called.
3. The constructor in the class is called.

Question 9

Overload vs overridden methods

Answer 9

Overload means providing a method with the same name but different signatures in any given type and overridden is used when we want that child class can change the behavior of a method from a parent class

Question 10

Boxing vs unboxing

Answer 10

Boxing refers to the process of converting a value type into a reference type and unboxing refers to the process of converting a reference type into a value type.

Question 11

Difference between implicit and explicit conversions

Answer 11

TBD

Question 12

Difference between “is” and “as” operators

Answer 12

The is operator determines whether a given object is in a particular class hierarchy or implements a specified interface, whereas the as operator takes a reference and a type, and returns a reference of the given type, or null if the reference cannot be made to refer to the object

Question 13

Why do we would use “as” operator instead of casting the object?

Answer 13

When casting an object to a specific type or instance, if the object is not possible to cast it’ll throw an exception, whereas if the as operator fails it returns a null reference and the program keeps running.

Question 14

What does a sealed class means?

Answer 14

A sealed class means, that this class can not be extended, so it cannot be used as the basis for another class.

Question 15

Abstract classes

Answer 15

TBD

Question 16

Yield keyword

Answer 16

TBD

Question 17

Which types does the System.Reflection namespaces contains?

Answer 17

1. Assembly
2. Method Info
3. Property Info
4. Type

Question 18

What allow us to control the iteration process in Parallel.For and Parallel.ForEach?

Answer 18

ParallelLoopState parameter added in the lambda expression that executes each iteration

Question 19

What is the return type of Parallel.For and Parallel.ForEach?

Answer 19

ParallelLoopResult, and can be used to determine whether or not a parallel loop has successfully completed

Question 20

What are the methods available to end the loop on Parallel.For and Parallel.ForEach with ParallelLoopState?

Answer 20

1. Stop()

2. Break()

Question 21

What are the methods available in PLINQ to in parallellism?

Answer 21

1. AsParallel()
2. AsSequential()
3. AsOrdered()
4. AsUnordered()
5. ForAll()

Question 22

How do we force parallelism when using PLINQ AsParallel method?

Answer 22

using the method:

WithExecutionMode(ParalllelExecutionMode.ForceParallelism)

Question 23

How does the AsOrdered method work in PLINQ?

Answer 23

It organizes the output in the same order as the original data, but it doesn’t prevent the parallelization of the query

Question 24

How does the AsSequential method work in PLINQ?

Answer 24

All the subsequent operators in the query run sequentially

Question 25

numbers.AsParallel.Select (“query”).AsSequential (). Where (“filter”). OrderBy (“sorting”) .AsParallel.GroupBy (“grouping”)

Answer 25

SELECT AsParallel
| | |
v v v
—————————————————-
WHERE AsSecuential
|
v
—————————————————-
ORDER BY
|
v
—————————————————-
GROUP BY AsParallel
| | |
v v v

Question 26

Differences between the three ways of converting values

Answer 26

1. “Parse” will throw an exception if the supplied argument is null or if a string does not contain text that represents a valid value.
2. “TryParse” will return false if the supplied argument is null or if a string does not contain text that represents a valid value.
3. “Convert” throws an exception if the supplied string does not contain text that represents a valid value, not throws exception if value is null, instead returns the default value for that type

Question 27

Cryptography vs cryptoanalysis

Answer 27

Cryptography is the business of rending a message unreadable to anyone except for the proper recipient of the message, cryptoanalysis is the business of code breaking.

Question 28

Symmetric vs asymmetric encryption

Answer 28

Symmetric encryption requires that both the sender and the receiver have the same key to encrypt and decrypt the message, asymmetric encryption does not requires to have the same key, however asymmetric keys requires more computer process and long messages

Question 29

Symmetric encryptions on .NET

Answer 29

AES => Advanced Encryption Standard
DES => Data Encryption Standard (Insecure)
RC2 => Insecure
Rijndael => AES was made based on this one
TripleDES => Used by the electronic payment industry, improves the DES standard by encrypting the incoming data three times