【疑问】new一个EnumMap ？

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#1 Created at ... [Delete] [Delete and Lock User]

new一个EnumMap的时候，

Map<DayOfWeek, String> map = new EnumMap<>(DayOfWeek.class);

为什么还需要在小括号里面指定 (DayOfWeek.class) 呀？

Map<DayOfWeek, String>

这句话已经说明了key的类型了呀

#2 Created at ... [Delete] [Delete and Lock User]

泛型擦除，方法内部从T拿不到class

#3 Created at ... [Delete] [Delete and Lock User]

谢谢老师，顾此失彼了，学到后面把前面的内容给忘了，尴尬

#4 Created at ... [Delete] [Delete and Lock User]

但是,好像value 不用加属这个参数

#5 Created at ... [Delete] [Delete and Lock User]

#4 Created at 2022/5/23 16:40

但是,好像value 不用加属这个参数

这个必须要加，构造器内部通过这个字节码对EnumMap进行了初始化

#6 Created at ... [Delete] [Delete and Lock User]

好问题