Introduction (C#)

Question 1

What is .Net?

Answer 1

It is a runtime similar to Java that executes Microsoft intermediate language (MSIL) at runtime.

Question 2

What are the three file types in a .Net project?

Answer 2

1. Solution files (.sln).
2. CS project files (.csproj).
3. Code files (.cs).

Question 3

What does solution files contain?

Answer 3

They contain a set of project files in a .Net project.

Question 4

What are CS project files and what do they contain?

Answer 4

1. They are the smallest buildable unit in a .Net project and they are build into a DLL or executable file (EXE file).
2. They can contain dependencies to other projects and build information (ant/make style).

Question 5

What do CS project files contain?

Answer 5

They contain C# code and belong to a C# project (.csproj).

Question 6

What is the style convention for methods in a .Net project?

Answer 6

Methods are always capitalized and uses the PascalCase.

Question 7

What is the style convention for variables in a .Net project?

Answer 7

Variables use camelCase.

Question 8

What are namespaces?

Answer 8

They are used to organize and group related classes and other types of code.

It is like a container that holds a collection of related classes, structures, and other types.

Question 9

Does package-scoped classes and methods exist in a .Net project?

Answer 9

No.

Question 10

What is the difference between a namespace and a package in a .Net project?

Answer 10

Namespaces are like a container that holds a collection of related classes, structures, and other types. It helps to organize code and avoid naming conflicts.

On the other hand, a package in Java is a collection of related classes and interfaces that are used to organize code and to provide a level of access protection and name-spacing.

Question 11

What does it mean when a public sealed class in a .Net project?

Answer 11

The keyword “sealed” is used to indicate that a class cannot be inherited or subclassed, similar to the “final” keyword in Java.

A public sealed class cannot be extended by other classes, and any attempts to do so will result in a compilation error.

Question 12

What does it mean when a final class is “sealed” and a final variable is “readOnly” in a .NET project?

Answer 12

1. Once a class is “sealed”, it cannot be inherited by any other class. This means that no further functionality can be added to the class by extending it.
2. Once a readonly variable is initialized, its value cannot be changed. This is useful for values that should not change during runtime, such as configuration settings or constants.

Question 13

What does the keyword “internal” mean?

Answer 13

It means that any class, method, or variable marked as internal can be accessed within the entire project, but not from outside the project or from other assemblies.

Question 14

What are override methods annotated as?

Answer 14

They are annotated as abstract, virtual or override.

Question 15

What are the differences in type names between Java and C#?

Answer 15

boolean is bool.
String is string.
Object is object.
List is IList.
HashMap is Dictionary.

Question 16

What is the difference in comparing strings between Java and C#?

Answer 16

In C#, strings can be compared using “ == “, while in Java you need to use the “equalsTo( )” method.

Question 17

What is the difference in numeric types between Java and C#?

Answer 17

In C#, numeric types have unsigned variants:
byte (-128..127).
ubyte (0..255).
uint (0..2^(32)-1).
ulong (0..2^(64)-1).

Question 18

What are some differences between generics in Java and C#?

Answer 18

Generics in C# are less fiddly as they are both a compile-time and run-time concept.

Question 19

What are Properties in a .Net project?

Answer 19

They are a way to define values for a class that can be accessed and modified from the outside. They are like variables or fields, but with additional functionality that allows you to control access and modification of their values.

Question 20

How are Properties different from fields in a .Net project?

Answer 20

They provide a way to encapsulate data, whereas fields are just variables that hold data. Properties can have validation, computed values, or other logic associated with them, while fields do not.

Question 21

What is the syntax for accessing a Property in .Net?

Answer 21

They can be accessed using syntax similar to accessing a field, such as “ int x = aClass.Value “.