为什么我的代码不能像我想要的那样工作？我如何检查日期的有效性？

问题描述

我想让用户插入她的名字并检查他是否插入了字符，否则让他插入一个有效的名字，并为卡号插入一个 6 整数，否则让他插入一个有效的number 然后插入到期日期。现在，如何检查插入的日期是否有效？

int  main()
{
    char name[20];
    int cardnumber,pin;
    float balance;    
    printf("Enter your first and last name :  ");
    scanf("%s",name);
    for (int i = 0; name[i] != '\0'; ++i)
    {
        if (!(name[i] >= 'a' && name[i] <= 'z')
         || !(name[i] >= 'A' && name[i] <= 'Z'))
        {  
            printf("The entered name is not all  Alphabet char plz insert a valid name\n");
            break;
        }
    }
    printf("insert your card number ~6 digit~\n ");
    scanf("%d",&cardnumber);
    if (!(sizeof(cardnumber) != 6)
     || !(cardnumber >= '0' && cardnumber <= '9'))
    {
        printf("plz insert a valid 6digit card number\n "); 
        scanf("%d",cardnumber);
    }
    struct date datei;
    printf("insert Expiration date of your card :\n");
    printf("day :");  
    scanf("%d",&datei.day);
    printf("month :");
    scanf("%d",&datei.month);
    printf("year :"); 
    scanf("%d",&datei.year);
    printf("Enter your acount Balance " );
    scanf("%d",&balance);
    printf("Enter your pin ~3digit~ :");
    // scanf("%d",&pin);
    // if (sizeof(pin)>3)
    // {printf("Enter a valid pin \n");
    // scanf("%d",&pin);}
    scanf("%d",pin);
    while (sizeof(pin) == 3)
    {
        printf("ENTER YOUR SECRET PIN NUMBER:");
        scanf("%d",&pin);
        if (sizeof(pin) != 3)
            printf("PLEASE ENTER VALID PASSWORD\n");
    }
}

解决方法

scanf("%d",cardnumber);
scanf("%d",datei.day);
scanf("%d",datei.month);
scanf("%d",datei.year);

您在这些陈述中遗漏了 &。将这些语句更改为：

scanf("%d",&cardnumber);
scanf("%d",&datei.day);
scanf("%d",&datei.month);
scanf("%d",&datei.year);