Section 1 QuestPond Udemy

Question 1

What’s the difference between a .NET and C#?

Answer 1

.Net is a framework and C# is a programming Language.

Question 2

What is an IL code?

Or What is JIT?

Answer 2

Intermediate language Code is the partailly compiled code. When a code has to run in a machine, it has to be compiled to a machine language. in .Net the code is first compiled to a IL language then JIT converts it to a machine language.

Question 3

Who compiles the IL code and how does it work?

Answer 3

IL code is compiled by JIT (Just in time compiler).

Question 4

Can we view the IL code?

Answer 4

we can view using ILDASM.exe

Question 5

What .Net converts to IL code?

Answer 5

Answer on your own.

Question 6

Does .Net supprots multiple languages?

Answer 6

Yes. It will get compiled to IL code.

Question 7

What is CLR?

Answer 7

Common Language Runtime invokes JIT to compile to IL code. Cleans any unused objects by GC>

Question 8

What is the difference between managed and unmanaged code?

Answer 8

Manages code runs under the control of CLR. Unmanaged code such as C++ dont use CLR.

Question 9

What is Garbage Collector?

Answer 9

Garbage Collector is a background process which cleans unused Managed resources.

Question 10

What is Garbage Collector?

Answer 10

Garbage Collector is a background process which cleans unused Managed resources.

for exmaple,

in a for loop create variable of object Customer..

for(i=0;i<=1000;i++)
{
 Customer x = new Customer();  
}

If we open in profiler, it we can see GC is cleaning those resources.

Question 11

Garbage collector cleans managed code, how do we clean unmanaged code?

Answer 11

TBD

Question 12

Explain the importance of CTS?

Answer 12

CTS (Common Type Syste,) ensures that data types defined in different languages gets compiled to a common data type.

Question 13

What is CLS?

Answer 13

CLS is a set of rules or guidelines when nay .Net language adhers to these sets of guidelines it can be consumed by any other languages in .Net.

Question 14

What is CLS?

Answer 14

CLS is a set of rules or guidelines when nay .Net language adhers to these sets of guidelines it can be consumed by any other languages in .Net.

Question 15

What is heap and stack?

Answer 15

They are memory types in an application. Stack stores primitive data types such as int double. In heap strings and objects are stored.

In stack, both variable and value is stored.

In heap, the variable in stored nin stack and it refers to the object in Heap.

Question 16

What are value types and reference types?

Answer 16

Value types contain actual data while reference typescontains pointer that point to the actual data.

Value types are stored in the satck and reference types are stored in the heap.

Question 17

What is boxing and unboxing?

Answer 17

Value to reference type is called bocing

int i = 10;

object j = i;

Question 18

How performance is affected due to boxing and unboxing?

Answer 18

TBD

Question 19

What is casting? Impliclit and explcit casting?

Answer 19

Casting is move from one DT to another DT.

Implcit casting: when we cast from lower datatype to higher dt is called implicit casting. ex:

int i =10;

double d = i;

double to int

expliit is opposit.

Question 20

What can happen in explicit casting?

Answer 20

we loose data. ex:

double 100.23;

int j - i. we lost .23…

Question 21

What are Array and Arraylist?

Answer 21

Array are fixed in size and they are strongly typed.

ArrayLists are not fixed.

Exampole,
int [] marr = { 1, 2, 3}

ArrayList myList = new ArrayList();
myList.Add(1);
myList.Add(“Shiv”);

Question 22

Which is better: Array or ArrayList?

Answer 22

ArrayList is bad becauyse it causes boxing and unboxing.

Question 23

WHat are Generic Collections?

Answer 23

Generic Collectios are strongly types and flexible. It has better performace as compared to ArrayList.

List li = new List();
li.add()

Question 24

What are threads in C#?

Answer 24

TBD

Question 25

how do you handle exceptions in C#?

Answer 25

use try
{
}
catch(exceptionex)
{
}

Question 26

What is finally block?

Answer 26

Finally block runs even when there is no exception. It runs irrespective of the exception. usually used to clean up.

Question 27

What is the use of Out keyword?

Answer 27

If we want to return multiple values from a function we will use out keyword.