Boxing and unBoxing

Boxing – This is the process of converting from value type to reference type. For example,

int myvar = 10;
object myObj = myvar;

UnBoxing – It’s completely opposite to boxing. It’s the process of converting reference type to value type. For example,

int myvar2 = (int)myObj;

Write a sample code to write the contents to text file in C#?

Below is the sample code to write the contents to text file –

Using System.IO;
File.WriteAllText(”mytextfilePath”, “MyTestContent”)

What is the difference between “continue” and “break” statements in C#?

• “continue” statement is used to pass the control to next iteration. This statement can be used with – “while”, “for”, “foreach” loops.
• “break” statement is used to exit the loop

Which are the loop types available in C#?

Below are the loop types in C# -

For
While
Do.. While

enum

enum keyword is used for declaring an enumeration, which consists of named constants and it is called as enumerator lists. Enums are value types in C# and these can’t be inherited. Below is the sample code of using Enums

Eg: enum Fruits { Apple, Orange, Banana, WaterMelon}

check whether hash table contains specific key in C#?

Method – “ContainsKey” can be used to check the key in hash table. Below is the sample code for the same –

Eg: myHashtbl.ContainsKey("1");

Explain Hashtable in C#?

It is used to store the key/value pairs based on hash code of the key. Key will be used to access the element in the collection. For example,

Hashtable myHashtbl = new Hashtable();
myHashtbl.Add("1", "TestValue1");
myHashtbl.Add("2", "TestValue2");