OnJava8-Examples/references/MutableInteger.java
2016-01-25 18:05:55 -08:00

35 lines
914 B
Java

// references/MutableInteger.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
// A changeable wrapper class
import java.util.*;
class IntValue {
private int n;
public IntValue(int x) { n = x; }
public int getValue() { return n; }
public void setValue(int n) { this.n = n; }
public void increment() { n++; }
@Override
public String toString() {
return Integer.toString(n);
}
}
public class MutableInteger {
public static void main(String[] args) {
List<IntValue> v = new ArrayList<>();
for(int i = 0; i < 10; i++)
v.add(new IntValue(i));
System.out.println(v);
for(int i = 0; i < v.size(); i++)
v.get(i).increment();
System.out.println(v);
}
}
/* Output:
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
*/