Most Asked C# Interview Q & A

Here are a few frequently asked C# interview questions and answers that help both beginners and experienced programmers achieve success in their interviews.

1. Mention the difference between Upcasting and Downcasting in C#?

Ans: Upcasting translates a particular type of object to a more common type, whereas Downcasting translates an item to a more specific type from a common type.

2. What are Jagged Arrays in C#?

Ans: Jagged Arrays are known as a collection of arrays that store arrays instead of numerical values. A jagged array can be created using two square brackets. The first bracket determines the size of an array, and the other bracket defines the size of an array to be saved.

3. What is the difference between the if-else statement and a switch statement?

Ans: An if-else statement runs a separate sequence of statements based on a true or false condition. A switch statement allows you to choose from numerous options to test for equality. Every value is known as a case, and every switch case is tried for the variable being turned on.

4. What is a Destructor?

Ans: Destructor is the opposite of a constructor that is a unique technique used in a class to delete objects or instances of a class.

5. Define a Multicast Delegate in C#.

Ans: Multicast delegates are also called Combinable delegates. Delegates that refer to different methods are known as Multicast Delegates. These delegates are an extended version of standard delegates.

6. Distinguish between Debug class and Trace class in C#.

Ans: Both Debug and Trace classes are the same. The Debug class and Trace class’s only difference is that the Debug class is used to test the project code, whereas the Trace class is used to try and launch the project code.

7. Mention the control statements used in C#.

Ans: ‘If’ is the most common control statement used in C#. There are four types of if control statements such as:

If – 'If' statement is used to validate whether a particular condition fulfills the condition required by the code or not. It returns true if the condition is suitable for the code.
If-else - 'If-else' statement is similar to the 'If' statement, but if the condition is false, it moves to the else statement and runs the remaining code present in the else block.
Nested if - 'Nested if' statement will search for another if statement inside the if statement, which is accurate and will proceed till the last if statement in it.
If-else-if - ’If-else-If' statement is similar to 'If-else' statement. Still, if the else statement is not valid, it moves to the remaining else conditions, and if none of them is correct, it runs the last else statement.

8. Mention the difference between late binding and early binding.

Ans: Early binding is also referred to as compile-time polymorphism. In early binding, we can have several same name methods but various types of parameters or even increase the number of parameters. Late binding is also referred to as run-time polymorphism. In late binding, we can use the same method name in different classes but not in the same class.

9. Distinguish between IEnumerable and Iqueryable?

Ans: IEnumerable is an interface that is useful to make an iteration over a non-generic array. Iqueryable can be best for LINQ and SQL queries. It is ideal for compiling a collection of databases.

10. What is a formatter in C#?

Ans: A formatter in C# is an object to encrypt text towards one side into messages and decrypt messages into text.

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