Constructors

[suresh.sa]

Hi Friends,

Good Morning to all...


Can anyone tell me is it possible to have private constructors, if so what is
the purpose of having a constructor as a private??



Regards,
Suresh.S.A.

[Zack]

You can have classes that cannot be "created" by other methods. These are used for classes with only static members.

Additionally, you can have private classes that can only be created internally. These are called singletons. Read more on such design patterns here.

[Tolls]

Or if you have an inner class that you want to expose to other classes, but you only want to allow it to be created inside the main class.
eg:

public class MyMainClass {
    public class MyInnerClass {
        private MyInnerClass() {
        }
    }
}

MyInnerClass can only be instantiated within an object of MyMainClass.

[Zack]

Even if it's public, you cant instantiate it from another class... can you? I've tried this before with no success.

[JosAH]

Even if it's public, you cant instantiate it from another class... can you? I've tried this before with no success.

That's most likely just a syntax issue:

new MyOuterClass( ... ). new MyInnerClass( ... );

kind regards,

Jos

[Zack]

Blargh. Tricky crap there. Thanks.