Polymorphism, continued

class Room

{

int id; // Id number of room

. . .

public String toString()

{ return ”Room: ” + id; }

}

class Bathroom extends Room

{

. . .

public String toString()

{ return ”Bathroom: ” + id; }

}

/* Client code. The class of the object, not the type of the variable, determines which method is invoked. */

Room r1 = new Room();

System.out.println(r1); // output: “Room: …”

Room r2 = new Bathroom();

System.out.println(r2); // output: “Bathroom: …”

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