第 35 条：用实例域代替序数

用实例域代替序数.jpeg

public enum Ensemble {
    SOLO, DUET, TRIO, QUARTET, QUINTET, SEXTET, SEPTET, OCTET, NONET, DECTET;
 
    public int numberOfMusicians() {
        return ordinal() + 1;
    }
}

public enum Ensemble {
    SOLO(1), DUET(2), TRIO(3), QUARTET(4), QUINTET(5), SEXTET(6), SEPTET(7), OCTET(8),
    DOUBLE_QUARTET(8), NONET(9), DECTET(10), TRIPLE_QUARTET(12);
 
    private final int numberOfMusicians;
 
    Ensemble(int size) {
        this.numberOfMusicians = size;
    }
 
    public int numberOfMusicians() {
        return numberOfMusicians;
    }
}