1.6. Object Initialization Expressions

The code in Listing 1-1 used another C# 3.0 feature called object initialization expressions:

List<Person> people = new List<Person> {
    new Person() { ID = 1,
                   IDRole = 1,
                   LastName = "Anderson",
                   FirstName = "Brad"},
    new Person() { ID = 2,
                   IDRole = 2,
                   LastName = "Gray",
                   FirstName = "Tom"}
            };

Just like an array initializer, an object initialization expression allows us to initialize a new object without calling its constructor and without setting its properties. Let's look at an example in Listing 1-6.

Example 1-6. Using an Object Initialization Expression

// The standard object creation and initialization
Person p1 = new Person();
p1. FirstName = "Brad";
p1.LastName = "Anderson";
ObjectDumper.Write(p1);

// The object initialization expression
Person p2 = new Person { FirstName="Tom", LastName = "Gray" };
ObjectDumper.Write(p2);

With object initialization expressions you can create an object directly and set its properties using just one statement. However, you can also write code like in Listing 1-4 without specifying the class you are instantiating.

.Select(p => new { p.FirstName, p.LastName }

It's not an error; it's another new feature called anonymous types, and I'll cover it next.