for(i=0;(c=str[i])!='\0';i++)
        if(c==' ')word=0;
        else if(word==0)
        {
            word=1;
            num++;
        }
        printf("There are %d words in the line.\n",num);

谁来帮我吧FOR改成while

i=0;
while((c=str[i])!='\0')
{      
       i++;
       if(c==' ')word=0;
        else if(word==0)
        {
            word=1;
            num++;
        }
}
 printf("There are %d words in the line.\n",num);

i=0;
while((c=str[i])!='\0')
{      
        if(c==' ')word=0;
        else if(word==0)
        {
            word=1;
            num++;
        }
       i++；
}
printf("There are %d words in the line.\n",num);
这样行不？

int main(int argc, char *argv[])
{
    char *str = "i hava a dream";
    char c;
    int word =0, num = 0;
   
    while (*str++) {
        if(c==' ')word=0;
        else if(word==0)
        {
            word=1;
            num++;
        }
    }
    printf("There are %d words in the line.\n",num);
   
    return 0;
}

貌似楼主这样不能得到真实word数目。

楼主的程序有问题，改了下
i=0;
while((c=str[i])!='\0')
{      
        if(c==' ')word=0;
        else
        {
            word=1;
            num++;
        }
       i++；
}
printf("There are %d words in the line.\n",num);