// references/Immutable1.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Immutable objects are immune to aliasing

public class Immutable1 {
 private int data;
 public Immutable1(int initVal) {
 data = initVal;
 }
 public int read() { return data; }
 public boolean nonzero() { return data != 0; }
 public Immutable1 multiply(int multiplier) {
 return new Immutable1(data * multiplier);
 }
 public static void f(Immutable1 i1) {
 Immutable1 quad = i1.multiply(4);
 System.out.println("i1 = " + i1.read());
 System.out.println("quad = " + quad.read());
 }
 public static void main(String[] args) {
 Immutable1 x = new Immutable1(47);
 System.out.println("x = " + x.read());
 f(x);
 System.out.println("x = " + x.read());
 }
}
/* Output:
x = 47
i1 = 47
quad = 188
x = 47
*/