Section 1: Multiple Choice

1. What is an enum in C#?

1. A collection of methods

2. A data type that stores multiple values in a list

3. A way to define a set of named integer constants

4. A class that can have multiple instances

Answer

1. A way to define a set of named integer constants

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2. What is the default access modifier in C#?

1. public

2. private

3. protected

4. internal

Answer

1. private

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3. What does sealed do in a class declaration?

1. Prevents it from being instantiated

2. Prevents it from being inherited

3. Prevents modification of its properties

4. Turns it into a static class

Answer

1. Prevents it from being inherited

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4. Which of these is a correct way to define a property in C#?

1. public string Name { get; set; }

2. public string Name() { get; set; }

3. public string Name = "default";

4. private string Name { get };

Answer

1. public string Name { get; set; }

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5. How do you declare an interface in C#?

1. class IExample {}

2. interface IExample {}

3. public static IExample {}

4. abstract IExample {}

Answer

1. interface IExample {}

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6. What will this code output?

int a = 10;
int b = a;
b = 20;
Console.WriteLine(a);

1. 10

2. 20

3. Null

4. Compilation error

Answer

1. 10

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7. What is the default value of an uninitialised bool variable in C#?

1. null

2. true

3. false

4. 0

Answer

1. false

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8. What does readonly do in C#?

1. Makes a variable accessible only inside a class

2. Allows modification only in the constructor

3. Prevents modification entirely

4. Applies to only static variables

Answer

1. Allows modification only in the constructor

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9. What happens if you do not explicitly set a value for an enum member?

1. It defaults to null

2. It takes the value 0 and increments for subsequent numbers

3. It must be set explicitly

4. It causes a compilation error

Answer

1. It takes the value 0 and increments for subsequent numbers

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10. How do you call a method in another class?

1. ClassName.MethodName();

2. MethodName.ClassName();

3. this.MethodName();

4. new MethodName();

Answer

1. ClassName.MethodName();