Classes and Inheritance - Illustrated C# 2005 - page 155

For example, the following code shows a constructor for class MyDerivedClass .

￿ The constructor initializer specifies that the base class constructor to use is the one that

has two parameters; the first parameter is a string , and the second parameter is an int .

￿ The parameters in the base parameter list must match the intended constructor's param-

eter list, in type and order.

Constructor initializer
↓
public MyDerivedClass( int x, string s ) : base( s, x )
{ ↑
... Keyword

When you declare a constructor without a constructor initializer, it is a shortcut for the
form with a constructor initializer consisting of base() , as illustrated in Figure 7-12. The two
forms are semantically equivalent.

Figure 7-12. Equivalent forms of a constructor

Another form of constructor initializer instructs the constructor to use a different con-
structor in the same class. For example, the following shows a constructor for class MyClass ,
which uses the constructor from the same class, but with two parameters, supplying a default
parameter as the second one.

Constructor initializer
↓
public MyClass(int x): this(x, "Using Default String")
{ ↑
... Keyword
}