Inner

package com.company;

public class Main {

    public static void main(String[] args) {
    // write your code here
Data data = new Data();
data.dataTampil();

    }

}

class Data {
    private int tinggi = 3;
    private int lebar = 4;

    class DalamData{
        void persegiPanjang(){
            System.out.println(tinggi*lebar);
        }
    }
    void dataTampil(){
        DalamData dalamData = new DalamData();
        dalamData.persegiPanjang();
    }
}