给定
1. public class SimpleCalc { 
2. public int value; 
3. public void calculate() { value += 7; } 
4. } 
和: 
1. public class MultiCalc extends SimpleCalc { 
2. public void calculate() { value -= 3; } 
3. public void calculate(int multiplier) { 
4. calculate(); 
5. super.calculate(); 
6. value *=multiplier; 
7. } 
8. public static void main(String[] args) { 
9. MultiCalc calculator = new MultiCalc(); 
10. calculator.calculate(2); 
11. System.out.println("Value is: "+ calculator.value); 
12. } 
13. }
结果为：