Classes and Objects | Java: Classes are custom/used data types, and Objects are instances of the data type. Syntax: Class: class_name { // statements... } Oject: class_name object_name = new class_name(); Here is the Code: import java.io.*; class Main { public static void main (String[] args) { A a = new A(); a.x = 1; System.out.println(a.x); B b = new B(); b.y = 2; b.z = 3; System.out.println(b.y); a.c = b; System.out.println(a.c.z); } } class A { int x; B c; } class B { int y; int z; } Output: 1 2 3 Here is the Video: