RosettaCodeData/Task/History-variables/Java/history-variables-2.java

26 lines
1.0 KiB
Java

public class TestIntegerWithHistory {
public static void main(String[] args) {
//creating and setting three different values
IntegerWithHistory i = new IntegerWithHistory(3);
i.set(42);
i.set(7);
//looking at current value and history
System.out.println("The current value of i is :" + i.get());
System.out.println("The history of i is :" + i.getHistory());
//demonstrating rollback
System.out.println("Rolling back:");
System.out.println("returns what was the current value: " + i.rollback());
System.out.println("after rollback: " + i.get());
System.out.println("returns what was the current value: " + i.rollback());
System.out.println("after rollback: " + i.get());
System.out.println("Rolling back only works to the original value: " + i.rollback());
System.out.println("Rolling back only works to the original value: " + i.rollback());
System.out.println("So there is no way to 'null' the variable: " + i.get());
}
}