vc++中itoa()这个函数不能实现应用什么替代

发布网友发布时间：2023-07-22 06:08

共2个回答

热心网友时间：2023-09-13 13:05

要不你试试自己增加一个

     /*============itoa=============*/
     /*把num转换成字符串存放在str 指向的字符串里*/

     int myitoa(int num, char *str)
     {
          int temp;
          int sign = 0;                          //标记num的符号

          char *p;

          if (str == NULL)    return -1;

          p = str;

          /*负数的话取绝对值并改变标记*/
          if (num < 0)
          {
                     num = 0 - num;
                     sign = 1;
          }

          /*把数从低位放进字符串*/
          do
          {
                     temp = num % 10;    //取num的最后一位
                     *(p++) = temp + '0';

          }while ((num /= 10) != 0);

          /*是负数的时候添加‘-’*/
          if (sign == 1)
          {
                    *(p++) = '-';
          }

           /*给字符串的末尾添加 ''/0*/
          *(p+1) = '/0';

          /*字符串逆置*/
          while(str < p)
          {
                   *str = *str + *p;
                   *p = *str - *p;
                   *str = *str - *p;

                   str++;
                   p--;
          }

          return 0;

      }

      /*========atoi========*/
      /*把str指向的字符串转换成数字*/

      #include <stdlib.h>

      int myatoi(const char *str)
      {
           int sum = 0;
           int sign = 0;

           if (str == NULL)
           {
                    perror("The string is NULL!/n");
                    exit(-1);
           }

           /*判断是否为负数*/
           if (*str == '-')
           {
                    sign = 1;
                    str++;
           }

           /*转换*/
           while (*str != '/0')
           {
                     sum = 10*sum + (*str - '0');
                     str++;
           }

            /*判断是否为负数*/
           if(sign == 1)
           {
                    sum = 0 - sum;
           }

           return sum;

      }

      另外还写 float 与字符串转换，代码如下


/*
*File : ftoa.c
*/

/*Float ===> String*/

int ftoa(char *str, float num, int n)        //n是转换的精度，即是字符串'.'后有几位小数
{
    int     sumI;
    float   sumF;
    int     sign = 0;
    int     temp;
    int     count = 0;

    char *p;
    char *pp;

    if(str == NULL) return -1;
    p = str;

    /*Is less than 0*/
    if(num < 0)
    {
        sign = 1;
        num = 0 - num;
    }

    sumI = (int)num;    //sumI is the part of int
    sumF = num - sumI;  //sumF is the part of float

    /*Int ===> String*/
    do
    {
        temp = sumI % 10;
        *(str++) = temp + '0';
    }while((sumI = sumI /10) != 0);

    /*******End*******/

    if(sign == 1)
    {
        *(str++) = '-';
    }

    pp = str;

    pp--;
    while(p < pp)
    {
        *p = *p + *pp;
        *pp = *p - *pp;
        *p = *p -*pp;
        p++;
        pp--;
    }

    *(str++) = '.';     //point

    /*Float ===> String*/
    do
    {
        temp = (int)(sumF*10);
        *(str++) = temp + '0';

        if((++count) == n)
            break;

        sumF = sumF*10 - temp;

    }while(!(sumF > -0.000001 && sumF < 0.000001));

    *str = '/0';

    return 0;

}

/*
* File : atof.c
*/

/*String ===> Float*/

float atof(const char *str)
{
    float   sumF = 0;
    int     sumI = 0;
    int     sign = 0;

    if(str == NULL) return -1;

    /*Is less than 0 ?*/
    if(*str == '-')
    {
        sign = 1;
        str++;
    }

    /*The part of int*/
    while(*str != '.')
    {
        sumI = 10*sumI + (*str - '0');
        str++;
    }

    /*Let p point to the end*/
    while(*str != '/0')
    {
        str++;
    }

    str--;          //Your know!

    /*The part of float*/
    while(*str != '.')
    {
        sumF = 0.1*sumF + (*str - '0');
        str--;
    }

    sumF = 0.1*sumF;

    sumF += sumI;

    if(sign == 1)
    {
        sumF = 0 - sumF;
    }

    return sumF;

}

转载一个大侠的代码

热心网友时间：2023-09-13 13:06

sprintf( );
或者 CString str;
str.Format( );