Question

Say I have this class:

class FooBar
{
    public FooBar() : this(0x666f6f, 0x626172)
    {
    }

    public FooBar(int foo, int bar)
    {
        ...
    }
 ...
}

If I did this:

FooBar foobar = new FooBar();

would the non-parameterized constructor execute first, then the parameterized one, or is it the other way around?

Answer 1

MSDN has a similar example with base:

public class Manager : Employee
{
    public Manager(int annualSalary)
        : base(annualSalary)
    {
        //Add further instructions here.
    }
}

And states:

In this example, the constructor for the base class is called before
the block for the constructor is executed.

Nevertheless, to be sure here’s my test:

class Program
{
    public Program() : this(0)
    {
        Console.WriteLine("first");
    }

    public Program(int i)
    {
        Console.WriteLine("second");
    }

    static void Main(string[] args)
    {
        Program p = new Program();
    }
}

Prints

second
first

so the parameterized constructor executes before the explicitly invoked one.