Programming In C# 70-483

Front 1

What three properties do OOP languages generally include?

Back 1

Encapsulation, Inheritance, Polymorphism

Front 2

What is encapsulation and what are two reasons it is important?

Back 2

To create a boundary around an object to seperate its external behavior from its private implementation. 1) ensures it is running how we want it to 2) prevents other from accessing the code and seeing how it works.

Front 3

What is Inheritance?

Back 3

Allowing objects to inherit from other objects.

Front 4

What is Polymorphism?

Back 4

The ability for an object to become other objects/other types.

Front 5

What does a managed language require to execute.

Back 5

A runtime environment, it is executed by a common runtime language.

Front 6

What is the building block of OOP languages that stores metadata about space allocation?

Back 6

A type.

Front 7

What are the three categories of types?

Back 7

Value types, Reference types, Pointer types.

Front 8

What is the purpose of the unified type system (UTS)?

Back 8

Identifies all the repetitive, universal types so they don't need to be created in every project.

Front 9

Name two ways C# implements inheritance.

Back 9

1)A class may inherit from a single base class, one and only one. 2)A class may implement zero or more interfaces.

Front 10

What are Lambda expressions?

Back 10

An unnamed method written inline. An enhancement of anonymous methods.

Front 11

Define: Anonymous types. When are they commonly used?

Back 11

Types without a design-time definition. Compiler inferred types. Used extensively with LINQ.

Front 12

What is the downside of anonymous types?

Back 12

They are not portable.

Front 13

What do extension methods do? When are they useful?

Back 13

Extend types without altering them. Useful for extending classes that are not yours or are sealed.

Front 14

Define: Dynamics

Back 14

Instruct the compiler to ignore type checking at compile time. Shuts down the security of the compiler. Ignores type checking until runtime.

Front 15

A class represents a ________ type and a struct represents a _________ type.

Back 15

reference, value.

Front 16

Define: value type

Back 16

directory stored values (int, boolean, double)

Front 17

Define: Reference type

Back 17

store a reference to data. Object instances, the value stored is a pointer to where the data is actually stored.

Front 18

When are some common scenarios where you should use a struct?

Back 18

1)Instances of the type are small

2)the struct is commonly embedded in another type

3)the struct logically represents a single value

4)the values don't change (immutable)

5)it is rarely boxed

Front 19

What type is an object?

Back 19

Reference type

Front 20

A class duplicates an ________ of an __________, while not duplicating the __________ of an _________ itself.

Back 20

instance, object, definition, object

Front 21

What does the static keyword do to a class and why would it be used?

Back 21

That class cannot be instantiated. Useful to expose static methods of that class so you can interact with them without the cost of instantiation.

Front 22

What does the abstract keyword do to a class?

Back 22

That class is incomplete, it must be completed in a derived class.

Front 23

What does the sealed keyword do to a class?

Back 23

That class cannot be inherited from.

Front 24

What does the partial keyword do to a class?

Back 24

Can be used to break up a class between multiple files. All properties will be compiled to one class at compile time.

Front 25

What is Entity Framework?

Back 25

An object-relational mapper that enables .NET devleopers to work with relational data using domain-specific objects. Eliminates the need for most of the data-access code to be manually written.

Front 26

What does the public keyword do?

Back 26

"Anyone can see this", a way around encapsulation.

Front 27

What does the private keyword do?

Back 27

Can only be used in the scope it is defined in.

Front 28

What does the internal keyword do?

Back 28

Can only be used in the scope of this assembly (project).

Front 29

What does the protected keyword do?

Back 29

Only scoped to this class and derived classes.

Front 30

What does the get; set; instruction provide for us?

Back 30

Instructs the compiler to create an infrastructure that will hold the value for the property defined.

Front 31

What does the virtual keyword do?

Back 31

Makes it so that this method can be overridden by inheriting classes.

Front 32

If a method is overridden in an inheriting class and then cast back to the originating class, will the method remain overridden or return to the original value?

Back 32

It will remain overridden.

Front 33

What does the new keyword do?

Back 33

Creates a brand new instance of the method, the original is not able to be referred to.

Front 34

What are generics?

Back 34

Introduce the concept of type parameters. Used when a strongly-typed collection is required.

Front 35

Define: Boxing

Back 35

The act of converting a value type to a reference type.

Front 36

Define: Unboxing. What "action" does it require?

Back 36

The act of converting a reference type to a value type. Unboxing requires a cast.

Front 37

What are the three type of statements that control flow?

Back 37

Selection, Iteration, Jump

Front 38

What is a ternary statement?

Back 38

an if statement shorthand

Front 39

What is the difference between a while and a do while statement?

Back 39

While evaluates the expression before executing the body so the body may execute 0 or more times.

Front 40

What are the three clauses of for loops (in order)?

Back 40

Initialization clause, conditional clause, iteration clause.

Front 41

What does the foreach loop do?

Back 41

Iterates over each element in an enumerable object.

Front 42

What does the is operator do?

Back 42

Returns true if an object is an instance of a type.

Front 43

What does the as operator do?

Back 43

Attempts to cast an object to a specified type.

Front 44

What happens if you attempt to cast an object using 'as' but the operation fails?

Back 44

The object is returned as null and no exception is raised.

Front 45

A string is immutable. What does this mean specifically if we attempt to change the string?

Back 45

A new string is returned.

Front 46

What class is a mutable implementation of a string?

Back 46

StringBuilder

Front 47

Define: Regular Expressions

Back 47

A specialized syntax to find and replace patterns in strings.

Front 48

What is reflection and why is it useful?

Back 48

Reflection inspects type metadata at runtime. This data can be used to create instances, access values, and execute methods dynamically at runtime.

Front 49

What is a constructor?

Back 49

A class method that is executed when an object of a given type is created.

Front 50

Identify the constructor:

Animal a = new Animal();

Back 50

Animal()

Front 51

What is a finalizer? When are finalizers commonly used?

Back 51

The inverse of a constructor. To release the resources created.

Front 52

Name two pieces of information the type metadata contains.

Back 52

1)The type name

2)The containing assembly

3)Constructors

4)Properties

5)Methods

6)Attributes

Front 53

What are the two ways to dynamically instantiate a type?

Back 53

1)Activator.CreateInstance

2)Calling Invoke on a ConstructorInfo object

Front 54

What is Garbage Collection? What does it collect?

Back 54

Automatic memory management. De-referenced objects (orphans).

Front 55

What is the IDisposable interface used for?

Back 55

Some objects need explicit code to release resources, IDisposable helps with that.

Front 56

What keyword is a shortcut for invoking Dispose on types that implement IDisposable?

Back 56

Using

Front 57

How are close, dispose and stop related?

Back 57

Close is functionally the same as Dispose but may be reopened. Stop is similar to close but can be restarted.

Front 58

What are memory leaks and how are they created?

Back 58

When objects that fall out of scope are referenced by objects in scope, keeping them alive.

Front 59

The Garbage Collector will assume an object is eligible for collection if it is only referred to by ______ _____________.

Back 59

Weak references

Front 60

What is a code contract?

Back 60

A system used for data validation.

Front 61

Code contracts have preconditions and post-conditions. What are the keywords for these conditions?

Back 61

Requires, ensures.

Front 62

Describe symmetric vs asymmetric encryption.

Back 62

Symmetric has only one key used for both encryption and decryption. Asymmetric has an outward facing public key and a private key used for decryption.

Front 63

True or false: Assemblies can be referenced by other assemblies.

Back 63

True

Front 64

Assembly vs. Namespace: Which is a logical container of code and which is a physical container of code.

Back 64

Assembly - physical

Namespace - logical

Front 65

What VS project type creates an assembly that can be shared?

Back 65

Class Libraries

Front 66

Portable Class Libraries can be shared across _________, while Windows Component Libraries (WinMD/metadata) can be shared across ___________.

Back 66

Platforms, languages.

Front 67

What is a Windows Runtime Component?

Back 67

A code library that can be used by all App Store development languages.

Front 68

Define: instrumentation

Back 68

Code that reports performance information.

Front 69

Define: telemetry

Back 69

Aggregating instrumentation for analysis.

Front 70

What is the GAC and what does it do?

Back 70

Global Assembly Cache. It creates a globally referenced set of assemblies on a machine.

Front 71

What are the advantages of opening a file for reading and opening a file as stream.

Back 71

reading - to keep open and keep writing.

stream - for large payloads and realtime processing.

Front 72

What do Environment Special Folders help you quickly access?

Back 72

Windows folders (documents, desktop, program files, etc)

Front 73

What is isolated storage?

Back 73

A data storage mechanism that provides isolation and safety by defining standardized ways of associating code with saved data.

Front 74

What is the namespace that contains methods to rename/move files?

Back 74

System.IO

Front 75

What is the namespace that contains methods to get file info?

Back 75

System.UI.FileInfo

Front 76

What is SOAP?

Back 76

Simple Object Access Protocol, standard for returning structured data from a Web Service as XML.

Front 77

What is REST?

Back 77

Representational State Transfer, a communications protocol. Uses less bandwidth than SOAP and typically returns XML or JSON.

Front 78

____________ _____________ maximizes resources on multicore systems by allowing units of work to be separated and completed.

Back 78

Asynchronous programming.

Front 79

What are the two keywords that simplify asynchronous programming?

Back 79

Async and await.

Front 80

What is LINQ?

Back 80

Language Integrated Query, a general-purpose query language that is integrated into .NET languages.