C# OOP MCQs

Question 1: Interface members have by default ______ accessibility.

• Public
• Private
• Internal
• None of the above

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Question 2: What to do if a class implements two interfaces which coincidently have one method with the same name and signature?

• Implement both interfaces implicitly.
• Implement at least one interface explicitly.
• A class cannot implement interfaces that have the same method name and signature
• A class cannot implement multiple interfaces.

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Question 3: Can one interface inherit from one or multiple interfaces in C#?

• Yes
• No

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Question 4: Which of the following types can implement interfaces?

• Class
• Struct
• Enum
• Event

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Question 5: Can we declare a protected member in an interface?

• Yes
• No
• Some times

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Question 6: Which of the following types can participate in inheritance in C#?

• Class, Struct, Interface
• Class, Enum, Interface
• Class, Object, Delegate
• All the reference types

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Question 7: Which of the following is not supported in C#?

• A class can inherit one or more classes
• A struct can inherit one or more classes
• An interface can inherit one or more classes
• All of the above

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Question 8: Which of the following statements is FALSE?

• Public members are always accessible and become part of the derived class object.
• Protected members are accessible in the derived class but cannot be a part of the derived class object.
• Internal members are accessible and become part of the derived class object if the base class and the derived class are in the same assembly.
• None of the above

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Question 9: A class can inherit one or more Struct.

• True
• False

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Question 10: What will be the output of the following program?

class Shape
{
    protected int Sides { get; set; }
}

class Square : Shape
{
    public int GetSides()
    {
        return this.Sides;
    }
}

Shape sq = new Square();
sq.Sides = 4;

• It will compile and run successfully.
• It will give a compile-time error.
• It will give a runtime error.
• Blank output.

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