Java实例化Java中的Short对象

Question

我想知道为什么我们可以这样做:

Long l = 2L;
Float f = 2f;
Double d = 2d;

甚至

Double d = new Double(2);

不是

Short s = 2s; //or whatever letter it could be

也不

Short s = new Short(2); //I know in this case 2 is an int but couldn't it be casted internally or something?

为什么我们需要使用 String 或 short 来构造函数。

Answer 1

但是您可以这样做:

Short s = 2;

或者这个:

Short s = new Short((short)2);

或者这个:

Short s = new Short("2");

只要数字在 [-2^15, 2^15-1] 范围内，上述任何方法都有效