查看用户输入以查看它是否为浮点数，始终返回true

Question

我试图提示用户论坛号码，并扫描它以查看它是否是浮点数。即使输入没有小数的数字，也会回来说它是浮点数。如果输入是浮点数，则函数应返回1，否则返回0。我觉得我的功能逻辑存在问题。任何帮助，将不胜感激。谢谢！

#include <stdio.h>   //including for the use of printf
#pragma warning(disable: 4996)      // turn off warning about sscanf()

/* == FUNCTION PROTOTYPES == */
double getDouble(double *pNumber);
double *pNumber = NULL;

int main(void)
{   
    double returnedValue = 0;
    double userInput = 0;
    int runOnce = 0;

    printf("Please Enter a float:");
    userInput = getDouble(&returnedValue);

    while (runOnce == 0)
    {
        if (userInput == 1)
        {
            printf("Your number is a valid float!\n");
            printf("%lf", returnedValue);
        }

        else
        {
            printf("Your number is not a float!\n");
        }

        printf("Press ENTER key to Continue\n");
        getchar();
    }
}



#pragma warning(disable: 4996)
double getDouble(double *pNumber)
{
    char record[121] = { 0 }; /* record stores the string from the user*/
    double number = 0;

    /* fgets() - a function that can be called in order to read user input from the keyboard */
    fgets(record, 121, stdin);

    if (scanf("%lf", &number) == 1)
    {
        *pNumber = number;
        return 1;
    }
    else
    {
        return 0;
    }
}

Answer 1

你叫fgets()和scanf()。使用其中一个但不是两个。如果您打算使用fgets()，请使用sscanf()来解析其结果。