An simple example of how interfaces are useful in Java.
public interface Enemy {
public int getHealth();
public void doNextTurn();
}Slime
public class Slime implements Enemy {
private static final int startingHealth = 30;
private int health;
public Slime() {
this.health = startingHealth;
}
@Override
public int getHealth() {
return health;
}
@Override
public void doNextTurn() {
if (health < 15) {
System.out.println("Do big attack");
} else {
System.out.println("I have lots of health");
}
}
public void getSlimed() {
System.out.println("HAHAHAHAHA you got slimed.");
}
}Goblin
public class Goblin implements Enemy {
private int health;
public Goblin() {
this.health = 22;
}
@Override
public int getHealth() {
return health;
}
@Override
public void doNextTurn() {
System.out.println("Me a goblin. Boom");
}
}// Making a room of `Enemy`s. Notice how we can make a list of `Enemy`s because both `Slime` and `Goblin` implement `Enemy`
List<Enemy> room = new ArrayList<>();
room.add(new Slime());
room.add(new Goblin());
room.add(new Slime());
// We can now iterate through the list of `Enemy`s and call `doNextTurn` because that method is defined in the `Enemy` interface
for (Enemy e: room) {
e.doNextTurn();
}