How creation an instance of inner class works?

snailp4el :

When I create an instance of inner class, I use this code.

OuterClass outerClass = new OuterClass();
OuterClass.InnerClass inerClass = outerClass.new InnerClass();

But I don't understand how outerClass.new InnerClass() works, why we use .new it like new its inner class, I understand it is not, but I do not understand the syntax.

oleg.cherednik :

An inner class is POJO. So, when you look in the target directory, you see 2 (two) class files. Therefore to create an instance of the inner class you use new.

OuterClass outerClass = new OuterClass();  // create instance
OuterClass.InnerClass inerClass = outerClass.new InnerClass();  // innerClass has `this` to outerClass instance

It means that InnerClass is not a static (i.e. has this reference to an object of OuterClass) and instance of OuterClass should be created prior to it.

OuterClass.InnerClass inerClass = new OuterClass.InnerClass();

It means that InnerClass is a static (i.e. has not this reference to an object of Outerlass) and it means, this is absolutely the same (from the JVM perspective) like two separate files with class OuterClass and class InnterClass.