Tag: C#

TechQuiz Question 7: Calling derived methods..

What is the result of the following code? using System; class Base {     public virtual void Foo(int x) { Console.WriteLine(“Base.Foo(int)”); } } class Derived : Base {     public override void Foo(int x)  { Console.WriteLine(“Derived.Foo(int)”); }     public void Foo(object o)  { Console.WriteLine(“Derived.Foo(object)”); } } class Test {     static void Main()     {         Derived d = new...

TechQuiz Question 6: Getting some closure…

What will be the output of the following code? using System; using System.Collections.Generic; class Test {     delegate void Printer();         static void Main()     {         List<Printer> printers = new List<Printer>();         for (int i = 0; i < 10; i++)         {             printers.Add(delegate { Console.WriteLine(i); });         }                 foreach (Printer printer in printers)        ...

TechQuiz Question 1 Why doesn’t my code throw an exception?

Inside VincisAqtion we’ve started with a little TechQuiz. We’re planning on  creating weekly questions to publish them on our intranet and next to the coffee machine. The first question is: Why doesn’t the following code throw an exception? static IEnumerable<char> CapitalLetters(string input){    if (input == null)    {        throw new ArgumentNullException(input);    }    foreach (char c in input)    {        yield return char.ToUpper(c);    }}          static void Main()         {             CapitalLetters(null);         } The code...