一、如何简单 快速 确认char/short/int/long类型的取值范围，示例如下：
/*
* @Description:
* @version: V1.0
* @Company: Twirling in time
* @Author: Lipingping
* @Date: 2019-06-29 19:01:45
* @LastEditors: Lipingping
* @LastEditTime: 2019-06-29 19:17:12
*/
#include <stdio.h>
#include <limits.h>
int main()
{
printf("About type: char\n");
printf("The value of INT_MAX is %i\n", CHAR_MAX);
printf("The value of INT_MIN is %i\n", CHAR_MIN);
printf("An takes %d bytes\n\n", sizeof(char));
printf("About type: signed short int\n");
printf("The value of INT_MAX is %i\n", SHRT_MAX);
printf("The value of INT_MIN is %i\n", SHRT_MIN);
printf("An takes %d bytes\n\n", sizeof(short));
printf("About type: int\n");
printf("The value of INT_MAX is %i\n", INT_MAX);
printf("The value of INT_MIN is %i\n", INT_MIN);
printf("An takes %d bytes\n\n", sizeof(int));
printf("About type: signed long int\n");
printf("The value of INT_MAX is %li\n", LONG_MAX);
printf("The value of INT_MIN is %li\n", LONG_MIN);
printf("An takess %d bytes\n\n", sizeof(signed long int));
return 0;
}
二、结论：
About type: char
The value of INT_MAX is 127
The value of INT_MIN is -128
An takes 1 bytes
About type: signed short int
The value of INT_MAX is 32767
The value of INT_MIN is -32768
An takes 2 bytes
About type: int
The value of INT_MAX is 2147483647
The value of INT_MIN is -2147483648
An takes 4 bytes
About type: signed long int
The value of INT_MAX is 9223372036854775807
The value of INT_MIN is -9223372036854775808
An takess 8 bytes三、Reason:
INT类型的取值范围取决于它最终对应的存储区域的大小。存储区域的大小是一个目标平台相关的信息，由编译器来决定。在一般的32位机器上，一个INT类型的变量最终会（由编译器）分配到4字节的内存区域，恰好是机器的字长。至于一个特定硬件平台的INT类型的大小，需要查看对应的编译器的文档。
如果要较好的移植性，考虑使用C99规范里定义的uint8_t，uint16_t等定长类型，他们保证在各种处理器编译器上结果是一样的，而且你可以用位移操作（bitwise operation），不用担心编译器和处理器的问题。
