The Unbeatable Quiz On C# Test

1. Can you inherit from multiple interfaces?

Yes

No

Yes, it is possible to inherit from multiple interfaces in programming languages that support multiple inheritance. This allows a class to inherit and implement the methods and properties defined in multiple interfaces, providing flexibility and the ability to fulfill multiple contracts. This feature is commonly used to achieve code reusability and to create more modular and flexible code structures.

Explanation

Yes, it is possible to inherit from multiple interfaces in programming languages that support multiple inheritance. This allows a class to inherit and implement the methods and properties defined in multiple interfaces, providing flexibility and the ability to fulfill multiple contracts. This feature is commonly used to achieve code reusability and to create more modular and flexible code structures.

2. Does c# support multiple inheritance?

Yes

No

Multiple inheritance is not supported. To achieve this, use interfaces.

Explanation

Multiple inheritance is not supported. To achieve this, use interfaces.

3. How do you keep your classes from being inherited or used as a base class?

Declare the class as Virtual

Declare the class as Private

Declare the class as Sealed

Declare the class as Internal

None of the above

Sealed. The developer trying to derive from your class will get a message: cannot inherit from Sealed class WhateverBaseClassName.

Explanation

Sealed. The developer trying to derive from your class will get a message: cannot inherit from Sealed class WhateverBaseClassName.

4. Which is true about the accessibility modifiers of methods within an Interface?

They are all declared as public by default

They are all declared as private by default

They are all declared as virtual by default

They are all declared as internal by default

They are all declared as sealed by default

The accessibility modifiers of methods within an Interface are all declared as public by default. This means that all methods within an Interface can be accessed and called from any other class or interface. There is no need to explicitly specify the public modifier for methods within an Interface as it is automatically assumed.

Explanation

The accessibility modifiers of methods within an Interface are all declared as public by default. This means that all methods within an Interface can be accessed and called from any other class or interface. There is no need to explicitly specify the public modifier for methods within an Interface as it is automatically assumed.

5. What is the difference between the System.String and System.StringBuilder class?

System.StringBuilder is immutable and System.String is mutable

System.StringBuilder is mutable and System.String is immutable

System.StringBuilder is a based on a class and System.String is based on a struct

The correct answer is that System.StringBuilder is mutable and System.String is immutable. This means that the value of a System.String object cannot be changed after it is created, while a System.StringBuilder object can be modified.

Explanation

The correct answer is that System.StringBuilder is mutable and System.String is immutable. This means that the value of a System.String object cannot be changed after it is created, while a System.StringBuilder object can be modified.

6. Structs are passed by Reference?

True

False

Structs cannot be inherited.
Structs are passed by value, not by reference.
Struct is stored on the stack, not the heap.

Explanation

Structs cannot be inherited.
Structs are passed by value, not by reference.
Struct is stored on the stack, not the heap.

7. How do you enforce garbage collection in .NET?

Garbage.Collect()

Collect()

This.Collect.Garbage()

System.GC.Collect()

In .NET, the System.GC.Collect() method is used to enforce garbage collection. This method forces an immediate garbage collection of all generations. It can be called explicitly to free up memory and reclaim resources that are no longer needed. The other options mentioned, Garbage.Collect(), Collect(), and this.Collect.Garbage(), are not valid methods for enforcing garbage collection in .NET.

Explanation

In .NET, the System.GC.Collect() method is used to enforce garbage collection. This method forces an immediate garbage collection of all generations. It can be called explicitly to free up memory and reclaim resources that are no longer needed. The other options mentioned, Garbage.Collect(), Collect(), and this.Collect.Garbage(), are not valid methods for enforcing garbage collection in .NET.

8. You have variable of type string name strValue. What are some of the ways this can be converted to a int?

Int.convert(strValue)

Convert.ToInt32(strValue)

Int32.Parse(strValue)

Int.value

Bool result = int32.TryParse(strValue, out i)

The given answer lists three methods to convert a string to an integer: Convert.ToInt32(strValue), int32.Parse(strValue), and bool result = int32.TryParse(strValue, out i).

Convert.ToInt32(strValue) is a method in C# that converts the specified string representation of a number to an equivalent 32-bit signed integer.

int32.Parse(strValue) is another method in C# that converts the string representation of a number to its 32-bit signed integer equivalent.

int32.TryParse(strValue, out i) is a method in C# that attempts to convert the string representation of a number to its 32-bit signed integer equivalent. It returns a boolean value indicating whether the conversion succeeded or failed, and the converted value is assigned to the out parameter 'i'.

Explanation

The given answer lists three methods to convert a string to an integer: Convert.ToInt32(strValue), int32.Parse(strValue), and bool result = int32.TryParse(strValue, out i).

Convert.ToInt32(strValue) is a method in C# that converts the specified string representation of a number to an equivalent 32-bit signed integer.

int32.Parse(strValue) is another method in C# that converts the string representation of a number to its 32-bit signed integer equivalent.

int32.TryParse(strValue, out i) is a method in C# that attempts to convert the string representation of a number to its 32-bit signed integer equivalent. It returns a boolean value indicating whether the conversion succeeded or failed, and the converted value is assigned to the out parameter 'i'.

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9. What are the different ways to overload a method?

Different parameter names

Different parameter data types

Different number of parameters

Different ordering of parameters

Changing the method name

The different ways to overload a method include using different parameter data types, different number of parameters, and different ordering of parameters. Overloading a method allows for multiple methods with the same name but different parameters, providing flexibility and versatility in method usage. By using different parameter data types, different number of parameters, or different ordering of parameters, we can create different versions of the method that can be called based on the specific arguments provided. This allows for more efficient and concise code, as well as accommodating various input scenarios.

Explanation

The different ways to overload a method include using different parameter data types, different number of parameters, and different ordering of parameters. Overloading a method allows for multiple methods with the same name but different parameters, providing flexibility and versatility in method usage. By using different parameter data types, different number of parameters, or different ordering of parameters, we can create different versions of the method that can be called based on the specific arguments provided. This allows for more efficient and concise code, as well as accommodating various input scenarios.

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