java - 奇怪的结果增加了一个超过其最大值的短路

Question

当我执行这段代码时，它给出的 s 值为 -7616。为什么这样？这是因为在将数据从 int 或其他东西转换为 short 时丢失了数据吗？

public static void main(String[] args) {
        // TODO code application logic here
       short s=0;
       int x=123456;
       int i=8;
       s +=x;
       System.out.println(s);

    }

Answer 1

你只是溢出了 short 的最大值:

short: The short data type is a 16-bit signed two's complement integer. It has a minimum value of -32,768 and a maximum value of 32,767 (inclusive). As with byte, the same guidelines apply: you can use a short to save memory in large arrays, in situations where the memory savings actually matters.

当有这样的溢出时会发生什么等同于这个算法:

/** Returns an integer which is equal to the short obtained by the ((short) n) conversion */
public static int int2short(int n) {
    int sign      = n > 0 ? 1 : -1;
    int increment = sign * (Short.MAX_VALUE - Short.MIN_VALUE + 1);
    for ( ; n > Short.MAX_VALUE || n < Short.MIN_VALUE ; n -= increment);
    return n;
}