不同位数的操作系统数据类型所占字节

在32位系统中：

sizeof(char) = 1

sizeof(short) = 2

sizeof(int) = 4

sizeof(long) = 4

sizeof(longlong) = 4

sizeof(float) = 4

sizeof(double) = 8

sizeof(long double) = 16

sizeof(p) = 4

在64位系统中：

sizeof(char) = 1

sizeof(short) = 2

sizeof(int) = 4

sizeof(long) = 8

sizeof(longlong) = 8

sizeof(float) = 4

sizeof(double) = 8

sizeof(long double) = 16

sizeof(p) = 8