We can achieve this by making everything in the class private. When someone tries to change any value, we don’t modify the existing object. Instead, we create a new object that has the old values plus the new value, and return the new object. This way, the original object retains its previous state. public final class Person { private final String name; private final int age; // Constructor public Person(String name, int age) { this.name = name; this.age = age; } // Getter methods public String getName() { return name; } public int getAge() { return age; } // "With" method to create a new object with a different name public Person withName(String newName) { return new Person(newName, this.age); } // "With" method to create a new object with a different age public Person withAge(int newAge) { return new Person(this.name, newAge); } }