Question

问题： Struct在编辑后会将数据保留在其中。

我有一个程序，它管理结构中的联系人，出于某种原因，当我更新联系人时，如果我选择不编辑它，它不会重置或将该字段留空。

更新功能：

void updateContact(struct Contact contact[], int update) {
    char contactInput[11] = { '\0' };
    int ans = 0;
    int contactIndex;
    int contactx;

    printf("Enter the cell number for the contact: ");
    getTenDigitPhone(contactInput);

    contactIndex = findContactIndex(contact, update, contactInput);
    contactx = findContactIndex(contact, update, contactInput);

    if (contactx == -1) {
        printf("*** Contact NOT FOUND ***\n");
    }
    else {
        printf("\nContact found:\n");
        displayContact(&contact[contactIndex]);

        printf("\nDo you want to update the name? (y or n): ");
        ans = yes();

        if (ans == 1) {
            getName(&contact[contactIndex].name);
        }

        printf("Do you want to update the address? (y or n): ");
        ans = yes();

        if (ans == 1) {
            getAddress(&contact[contactIndex].address);
        }

        printf("Do you want to update the numbers? (y or n): ");
        ans = yes();

        if (ans == 1) {
                getNumber(&contact[contactIndex].numbers);
        }      
    }    
}

STRUCT：

struct Contact contact[MAXCONTACTS] =
{       {           { "Rick", { '\0' }, "Grimes" },
        { 11, "Trailer Park", 0, "AJA 2J2", "King City" },
        { "4161112222", "2162223333", "4163334444" }        },

    {           { "Maggie", "R.", "Greene" },
        { 55, "Hightop House", 0, "A9A 3K3", "Bolton" },
        { "9051112222", "9052223333", "9053334444" }        },

getNumber功能：

void getNumber(struct Number *num) {
    int response;

    printf("Please enter the contact's cell phone number: ");
    getTenDigitPhone(num->cell);
    //      scanf("%10s", num->cell);
    //      *num->cell = getInt();

    printf("Do you want to enter a home phone number? (y or n): ");
    response = yes();

    if (response == 1) {
        printf("Please enter the contact's home phone number: ");
        getTenDigitPhone(num->home);
        //      scanf("%10s", num->home);
        //      *num->home = getInt();
    }

    printf("Do you want to enter a business phone number? (y or n): ");
    response = yes();

    if (response == 1) {
        printf("Please enter the contact's business phone number: ");
        getTenDigitPhone(num->business);
        //      scanf("%10s", num->business);
        //      *num->business = getInt();
    }    }

我想在更新联系人后将该字段留空（如果我没有更新）。我不知道如何删除成员结构，所以请帮助我，我将非常感激。

Answer 1

将struct字段设置为空指针，或指向“my blank string”的指针 *num->cell = 0;

如果你这样做，你将不得不在以后检查null。

或者您可以执行*num->cell = myBlankString;，其中空白字符串定义为
char myBlankString[1] = ""; 这是一个可打印的空白字符串。

在C中删除结构的成员

1 个答案: