一个蛮有意思的类

[limao1358]

package test;

public class Suit implements Comparable {
private final String name;

private static int nextOrdinal = 0;

private final int ordinal = nextOrdinal++;

private Suit(String name) {
this.name = name;
}

public String toString() {
return name;
}

public int compareTo(Object o) {
return ordinal - ((Suit) o).ordinal;
}

public static final Suit CLUBS = new Suit("clubs");

public static final Suit DIAMONDS = new Suit("diamonds");

public static final Suit HEARTS = new Suit("hearts");

public static final Suit SPADES = new Suit("spades");

}

[sxnucseven]

乱

[leishuo]

final 只能初使一次

[limao1358]

这个类是绝对正确的,大家不要怀疑,他提供了不可变的枚举特性.另外还可以比较排序.

[limao1358]

楼上的指的是"private final int ordinal = nextOrdinal++;"吗?不要忘了它是实例变量,每创建一个类就又会生成一个的.