Tag: .net

Questions Related to .net

Polymorphism occurs when the methods of the child class.

.net c-sharp

  1. Override the parent class methods but maintain the implementation

  2. Maintain the same return type and arguments as the parent class, but implement it differently

  3. Have different return types and arguments than the parent class

  4. Are Virtual

Show answer
Correct Option: B

AI Explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) Override the parent class methods but maintain the implementation - This option is incorrect. Polymorphism does involve overriding methods from the parent class, but it allows for changing the implementation of these methods, not maintaining the same implementation.

Option B) Maintain the same return type and arguments as the parent class but implement it differently - This option is correct. Polymorphism occurs when a child class provides a different implementation of a method that is already defined in the parent class. The method in the child class must have the same return type and arguments as the method in the parent class.

Option C) Have different return types and arguments than the parent class - This option is incorrect. Polymorphism requires the child class method to have the same return type and arguments as the parent class method. Having different return types and arguments would result in method overloading, not polymorphism.

Option D) Are Virtual - This option is incorrect. Virtual methods in object-oriented programming languages allow for method overriding, but they are not a requirement for polymorphism. Polymorphism can occur with or without virtual methods.

The correct answer is B. This option is correct because it accurately describes polymorphism, where the child class methods maintain the same return type and arguments as the parent class methods but implement them differently.

To output the value of multidimensional array, Console.WriteLines(___)
.net c-sharp

  1. myArray[1][3];

  2. myArray[1,3];

  3. myArray{1}{3};

  4. myArray(1),(3);

Show answer
Correct Option: B
Explanation:

To output the value of a multidimensional array, you need to provide the indices for each dimension of the array. Let's go through each option and determine if it correctly outputs the value of a multidimensional array:

A. myArray[1][3]; This option is incorrect because it uses the wrong syntax to access the value of a multidimensional array. In C#, the correct syntax to access a value in a multidimensional array is myArray[1,3], not myArray[1][3]. The correct syntax uses commas to separate the indices for each dimension.

B. myArray[1,3]; This option is correct. It uses the correct syntax to access the value of a multidimensional array. The comma is used to separate the indices for each dimension, and this syntax correctly outputs the value at index 1 in the first dimension and index 3 in the second dimension of the array.

C. myArray{1}{3}; This option is incorrect because it uses curly braces instead of square brackets to access the value of the multidimensional array. In C#, square brackets [] are used to access array elements, not curly braces {}.

D. myArray(1),(3); This option is incorrect because it uses parentheses instead of square brackets to access the value of the multidimensional array. In C#, square brackets [] are used to access array elements, not parentheses ().

Therefore, the correct option is B. myArray[1,3].

All methods in an abstract base class must be declared abstract.
.net c-sharp

  1. True

  2. False

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Correct Option: B

Methods that are declared abstract in the base class must show implementation at the time of declaration.
.net c-sharp

  1. True

  2. False

Show answer
Correct Option: B

The code public class B : A { }
.net c-sharp

  1. Defines a class that inherits all the methods of A

  2. Defines a class that inherits the public and protected methods of A only

  3. Errors

  4. a and b

Show answer
Correct Option: B

Assuming that public class B : A { public B(int i) :base(i) { } } compiles and runs correctly, what can we conclude about the constructors in the class A?

.net c-sharp

  1. One constructor takes an argument of type i

  2. There is only a default constructor

  3. One constructor takes an arguments of the type int

  4. a and b

Show answer
Correct Option: C

AI Explanation

To answer this question, let's analyze the given code:

public class B : A {
    public B(int i) : base(i) {
    }
}

This code snippet shows the class B inheriting from class A. The constructor in class B takes an argument of type int and calls the base constructor of class A with the same argument.

Based on this information, we can conclude that:

A. One constructor takes an argument of type i - This option is incorrect because the argument in the constructor of class B is named i, not i itself.

B. There is only a default constructor - This option is incorrect because the presence of the B(int i) constructor in class B indicates that there is a non-default constructor in class A.

C. One constructor takes an argument of the type int - This option is correct because the B(int i) constructor in class B calls the base constructor A(int i), indicating that there is a constructor in class A that takes an argument of type int.

D. a and b - This option is incorrect because option A is incorrect. Only option C is correct.

Therefore, the correct answer is option C.

Classes declared with the sealed keyword cannot be base class.
.net c-sharp

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

To solve this question, the user must understand the concept of the sealed keyword in object-oriented programming languages.

Explanation:

The sealed keyword is used to restrict inheritance in object-oriented programming. When a class is declared with the sealed keyword, it means that no other class can inherit from it. In other words, a sealed class cannot be used as a base class for another class.

Now, let's go through each option and explain why it is right or wrong:

A. True: This option is correct. When a class is declared with the sealed keyword, it cannot be used as a base class. Other classes cannot inherit from a sealed class.

B. False: This option is incorrect. Classes declared with the sealed keyword cannot be used as a base class, so the statement is true.

The Answer is: A

A method_____an exception when that method detects that a problem has occured.
.net c-sharp

  1. Trys

  2. Catches

  3. Throws

  4. a and b

Show answer
Correct Option: C

Exception objects are derived from the class.
.net c-sharp

  1. Try

  2. Catch

  3. Exception

  4. Event

  5. System

Show answer
Correct Option: C

An abstract class
.net c-sharp

  1. may contain instance variables

  2. may contain constructors

  3. may extend another class

  4. a and b

  5. all of the above

Show answer
Correct Option: E