Question

In Java, the standard way to create an object is using

MyClass name = new MyClass();

I also often see the construct

new MyClass() { /*stuff goes in here*/ };

I’ve been looking online for a while and can’t find a good explanation of what the second construct style does or how it does it.

Can someone please explain how and why you would use the second construct?

Answer 1

This construct makes actually two things: 1) It declares an anonymous class which extends the class you use in the constructor and 2) creates an instance of this anonymous class.

Edit: When using such a construct you can observe the anonymous class by looking at the generated .class files. There is the normal MyClass.class file and another one for each anonymous subclass: MyClass$1.class for the first and so on.