Unit 3

Which of the following is a reference type in C#?

• A) int

• • B) double

• • C) string

• • D) char

Which of the following statements is true regarding implicit and explicit conversion in C#?

• • A) Implicit conversion requires a cast operator.

• • B) Explicit conversion occurs automatically by the compiler.

• • C) Implicit conversion may result in data loss.

• • D) Explicit conversion is also known as widening conversion.

What does null represent in programming languages?

• • D) A reserved keyword for method declarations

• • C) A reference to nothing or absence of a value

• • B) An undefined variable

• • A) A value representing an empty string

Which of the following statements about arrays in C# is false?

• • A) Arrays can store elements of different types.

• • B) Arrays have a fixed size that cannot be changed.

• • C) Elements in an array are accessed using indices.

• • D) Arrays in C# are homogeneous, meaning they can store elements of the same type.

How would you declare and initialize an array of integers with values 1, 2, and 3 in C#?

• • A) int[] arr = new int[] {1, 2, 3};

• • D) int arr[3] {1, 2, 3};

• • ;

  • C) int arr[3] = {1, 2, 3};

• • B) int[] arr = {1, 2, 3};

Which of the following statements about the Common Type System (CTS) is true?

• • A) CTS ensures compatibility only between C# and VB.NET.

• • B) CTS defines data types that are specific to each .NET language.

• • C) CTS ensures consistency and interoperability of types across different .NET languages.

• • D) CTS is a feature specific to the C# language.

In object-oriented programming (OOP), which principle emphasizes hiding the internal state of an object and only exposing the necessary functionalities?

• • A) Encapsulation

• • D) Abstraction

• • B) Inheritance

• • C) Polymorphism

What is the purpose of nullable types in C#?

• • C) To improve performance by reducing memory usage

• • B) To restrict variables from being assigned null values

  • ping in the language

• • A) To allow variables to be assigned null values

• • D) To enforce strong typing in the language

How do you access the third element in an array named arr in C#?

• • A) arr[2]

• • D) arr.3

• • C) arr(3)

• • B) arr[3]

What is the default value of a reference type variable in C# if it is not explicitly initialized?

• • A) 0

• • D) null

• • B) ""

• • C) False