学步园

class Cleanser
{
private String s ="Cleanser";
public void append(String a)
{
s+=a;
}
public void dilute()
{
append("dilute()");
}
public void apply()
{
append("apply()");
}
public void scrub()
{
append("scrub()");
}
public String toString()
{
return s;
}
public static void main(String args[])
{
Cleanser x = new Cleanser();
x.dilute();
x.apply();
x.scrub();
System.out.println(x);
}
}

public class Detergent extends Cleanser
{
public void scrub()
{
append("Detergent.scrub");
super.scrub();
}

public void foam()
{
append("foam()");

}
public static void main(String args[])
{
Detergent x = new Detergent();
x.dilute();
x.apply();
x.scrub();
x.foam();
System.out.println(x);
System.out.println("testing base class:");
Cleanser.main(args);

}
}