I private constructor is a constructor that is only available to the
same class. They can be useful in factory scenarios, where a class
creates other instances of its own class and you don't want other
classes to be able to instantiate the class in the same way.
For example:
public class Foo {
string name;
// this is the only constructor available to other classes
// other classes cannot set the name field directly
public Foo(){
this.name = "DefaultName";
}
// this constructor is not available to other classes
// it allows the name field to be set
private Foo(string name){
this.name = name;
}
// other classes can call this factory method
public Foo CreateFoo(string fooName){
// calls the private constructor
// and returns a new Foo with the name "fooName"
return new Foo(fooName);
}
public string Name { get { return this.name; } }
}
You can also have static constructors, which can be used to initialize
static fields of the class.
static Foo() { // initialize static fields }
Joshua Flanagan
http://flimflan.com/blog
Sathyaish wrote:
What is a private constructor, and why would a class have one? What are
the other kinds of constructors besides:
(1) public constructors; and
(2) parameterized constructors
And I understand that they are not mutually exclusive of one another.
The above classification assimilates my knowledge of having used
constructors in both the above manners.
