只是一个简单的米和英尺转化的程序，我设置的精度为double，结果显示错误，请帮我查找下错误：
double\float到底有什么区别呢？？？
#include <stdio.h>

double Transform1();
double Transform2();
void main() //meter and feet bilateral transform
{

    printf("please choose the mode you want to transform:\n");
    printf("a. from meter to feet\n");
    printf("b. from feet to meter\n");
    char s;
    s =    getchar();

    switch(s)
    {
   
    case 'a': Transform1();break;
    case 'b': Transform2();break;

    }

}


double Transform1()
{

    printf("you have selected the mode (from meter to feet), please input the number:\n");
    double temp, res;
    scanf("%f",&temp);
    res=temp*3.28;
    printf("the result is :%f\n",res);
    return res;
}

double Transform2()
{

    printf("you have selected the mode (from feet to meter), please input the number:\n");
    double temp, res;
    scanf("%f",&temp);
    res=temp*0.3;
    printf("the result is :%f\n",res);
    return res;
}

你的res返回给谁呀？

返回给函数啊！！不对吗？？

与那个好像关系不大吧？？好像把double改成float 就对了！不明白原因，愿高手解答！！

    #include <stdio.h>


 double Transform1();
double Transform2();
void main() //meter and feet bilateral transform
{

    printf("please choose the mode you want to transform:\n");
    printf("a. from meter to feet\n");
    printf("b. from feet to meter\n");
    char s;
    s =    getchar();

    switch(s)
    {
    
    case 'a': Transform1();break;
    case 'b': Transform2();break;

    }

}


double Transform1()
{

    printf("you have selected the mode (from meter to feet), please input the number:\n");
    double temp, res;
    scanf("%lf",&temp);//%lf
    res=temp*3.28;
    printf("the result is :%f\n",res);
    return 0;
}

double Transform2()
{

    printf("you have selected the mode (from feet to meter), please input the number:\n");
    double temp, res;
    scanf("%lf",&temp);//%lf
    res=temp*0.3;
    printf("the result is :%f\n",res);
    return 0;
}

[ 本帖最后由 遮天云 于 2010-11-17 20:45 编辑 ]

#include <stdio.h>

void Transform1();
void Transform2();
void main() //meter and feet bilateral transform
{

    printf("please choose the mode you want to transform:\n");
    printf("a. from meter to feet\n");
    printf("b. from feet to meter\n");
    char s;
    s =    getchar();

    switch(s)
    {
   
    case 'a': Transform1();break;
    case 'b': Transform2();break;

    }

}


void Transform1()
{

    printf("you have selected the mode (from meter to feet), please input the number:\n");
    double temp, res;
    scanf("%lf",&temp);
    res=temp*3.28;
    printf("the result is :%lf\n",res);
    //return res;  访问值干什么啊！
}

void Transform2()
{

    printf("you have selected the mode (from feet to meter), please input the number:\n");
    double temp, res;
    scanf("%lf",&temp);  // 双精度double型输入格式是这样的！你写的那个是单精度float型的输入格式
    res=temp*0.3;
    printf("the result is :%lf\n",res);
   // return res;
}

[ 本帖最后由 m21wo 于 2010-11-17 20:46 编辑 ]

谢谢啊

感觉到了差距