object initializers

To get started, let's look at the standard way of initializing an object with data in C# 2.0 using constructors.  The following example creates a Person object and passes three values to its constructor.

Person p = new Person("John", "Doe", "602-123-1234");

As mentioned, C# 3.0 now supports the concept of "object initializers" which means you can easily assign data to specific properties in a type with having to create an explicit constructor (you can of course still create constructors as well). The standard C# { and } brackets are used to create object initializers.  Here's an example of using an object initializer to assign property data to a Person type.  It's nice because doing the same thing without using a constructor in C# 2.0 would have resulted in around 5 lines of code which is too many for something simple like property value assignments.

Person p = new Person() {FirstName="John",LastName="Doe",Phone="602-123-1234",City="Phoenix"};

If the Person type defines a sub object as a property you can even use object initializers to create the sub object. Here's an example of defining an Address object:

Person p = new Person()
{
    FirstName = "John",
    LastName = "Doe",
    Address = new Address()
    {
        Street = "1234 St.",
        City = "Phoenix"
    }
};