package ch04;

import java.applet.*;
import java.awt.*;

class Chengji {
    float fun(float x, float y) {
        return x * y;
    }
}

class AddChengji extends Chengji {
    float fun(float x, float y) {
        return x + y;
    }
}

public class TestAddChengji extends Applet {
    AddChengji sum;

    public void init() {
        sum = new AddChengji();
    }

    public void paint(Graphics g) {
        g.drawString("sum=" + sum.fun(4, 6), 100, 40);
    }
}