woaidongmao

1、可以在文件里面保存為有符號整形，但是讀入到內存變成無符號的。

2、可以在文件里面保存為無符號整形，但是讀入到內存變成有符號的。

// testSignelToUnsign.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
int main(int argc, char* argv[])
{
    char szBuf[] = "-1";
    int s_int = 0;
    unsigned int  us_int = 0;
    s_int = atoi(szBuf);
    printf("s_int:%d\n", s_int);//---- -1
    us_int = (unsigned int)atoi(szBuf);
    printf("us_int:%u\n", us_int);//---- 4294967295
    memcpy(&us_int, &s_int, sizeof(unsigned int));
    printf("us_int:%u\n", us_int);//---- 4294967295
    return 0;
}

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
int main(int argc, char* argv[])
{
    char szBuf[] = "4294967295";
    int s_int = 0;
    unsigned int  us_int = 0;
    s_int = atoi(szBuf);
    printf("s_int:%d\n", s_int);//---- -1
    us_int = (unsigned int)atoi(szBuf);
    printf("us_int:%u\n", us_int);//---- 4294967295
    memcpy(&us_int, &s_int, sizeof(unsigned int));
    printf("us_int:%u\n", us_int);//---- 4294967295
    return 0;
}