Console.Writeline basics

Question

I have a question about the following code:

class CurrentDate
    {
        static void Main()
        {
            Console.WriteLine(DateTime.Now);
                


        

Answer 1

Contrary to what some persons think, DateTime.ToString() won't be called. In .NET, an object can have two ways to "stringize" itself: overriding the string Object.ToString() method and implementing the IFormattable interface. DateTime does both.

Now... When you try doing

Console.WriteLine(DateTime.Now);

the void public static void WriteLine(Object value) overload is selected (you can see it if you Ctrl+Click on WriteLine in Visual Studio). This method simply calls the TextWriter.WriteLine(value) method, that does:

IFormattable f = value as IFormattable;
if (f != null)
    WriteLine(f.ToString(null, FormatProvider));
else
    WriteLine(value.ToString());

All of this can be easily seen using ILSpy and looking for the Console.WriteLine.