Java 中 x=-x 无效

  int x=-2147483648;
        x=-x;
        System.out.print(x);

long 放的位置不一样就会出现不同的结果

 @Test

    public void test4() {
        int a = -2147483648;
        long x=-(long)a;
        long x1=(long)-a;
        System.out.print(x);  //2147483648
        System.out.print(x1); //-2147483648

    }