C# Test 5

Question 2: Which of the following can contain event declarations?

• Class
• Interface
• Struct
• All of the above

Question 3: What will be the output of the following program?

static void Main(string[] args)
{
    Action<int> DoSomething = i => Console.Write(i);
       
    DoSomething(50);
}

• 50
• 0
• Compile-time error
• Runtime error

Question 4: Which of the following statement is TRUE?

• Anonymous method can access outer variables or functions.
• Anonymous method cannot contain jump statements like goto, break or continue.
• Anonymous method cannot access ref or out parameter of an outer method.
• All of the above.

Question 5: Which of the following can be defined generic?

• Class
• Struct
• Delegate
• Enum

Question 6: Which of the following generic constraints restricts the generic type parameter to an object of the class?

• class Processor<T> where T:class
• class Processor<T> T:object
• class Processor<T>: where T=new()
• class Processor<T> where T:new()

Question 7: Interface members are ______ by default.

• Private
• Public
• Internal
• None of the above

Question 8: 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.

Question 9: Can one interface inherit from one or multiple interfaces in C#?

• Yes
• No

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.

Question 11: What will be the output of the following program?

class Person
{
    public void Introduction(int age, string name){ 
        Console.WriteLine("My name is " + name);
    }
        
    public void Introduction(string name, int age=0){ 
        Console.WriteLine($"My name is {name} and I am {age} years old");
    }      
}
Person p = new Person();
p.Introduction("Steve");

• My name is Steve
• My name is Steve and I am 0 years old.
• Compile-time error
• Run-time error

Question 12: What will be the output of the following program?

class Printer
{
    public virtual void Install()
    {
        Console.WriteLine("Printer Installed.");
    }

    public virtual void Print(string text)
    {
        Console.WriteLine("Printing: " + text);
    }
}

class LaserPrinter : Printer
{
    public void Install()
    {
        Console.WriteLine("Laser Printer Installed Successfully.");
    }
        
}

Printer myprnt = new LaserPrinter();
myprnt.Install();

• Printer Installed.
• Laser Printer Installed Successfully.
• Compile-time error
• Run-time error

Question 13: Which of the following static class will you use for file I/O operations?

• FileInfo
• File
• Directory
• Path

Question 14: Which of the following class is the base class for all I/O operations from different sources?

• System.IO.Stream
• System.IO.FileStream
• System.IO.MemoryStream
• System.IO.NetworkStream

Question 15: What will be the output of the following C# 7.0 code?

public class Program
{
	public static void Main()
	{
		var input = "100";
		if (int.TryParse(input, out int result))
			Console.WriteLine(result);
		else
			Console.WriteLine("Could not parse input");
	}
}

• Compile-time error
• Runtime error
• 100
• Could not parse input