c - 输入代码..错误:entery. exe停止工作。 C语言

Question

此代码应该获取输入的用户名和密码。用户名是 Admin，密码是 2016。如果用户输入正确，它将打印登录过程已成功完成，否则它将要求用户输入他们再次..我编写了代码，但它不起作用，我不知道为什么..这里是:

#include <stdio.h>
int main(){
    char* *username[5]; int password,choice; char Admin,i;

    printf("Welcome to the Students' Registration System\n");
    printf("Dear Registry employee: Kindly insert your username:\n");
    for (i=0;i<5;i++){
        scanf("%c", &username[i]);  
    }
    printf("Insert your password:\n");
    scanf("%d", &password);


    if ((*username[5]=="Admin")&&(password==2016))
    printf("The login process is successfully done");
    else 
    while ((*username[5]!="Admin")||(password!=2016))
   {
        printf("The login process failed\n");
        printf("Dear Registry employee: Kindly insert the correct username and password\n");
        for (i=0;i<5;i++){
            scanf("%c", &username[i]);
        }
        scanf("%d", &password); 
    }

    printf("Please choose the number of your next step:\n");
    printf("[1]Add new student\n");
    printf("[2]Add new course\n");
    printf("[3]Assign\remove courses for the student\n");
    printf("[4]Search and view students' details:\n");
    printf("[5]Request reports:\n"); 
    printf("[6]Update student/course record:\n");
    printf("[7]Delete student/course record:\n");

    return 0;
 }

Answer 1

您的程序存在多个问题，其中包括:

• 将用户名声明为指向字符指针的指针数组
• 用户名的长度不足以保存默认密码admin
• 使用循环读取用户名。
• 使用 == 和 != 运算符比较字符串。

更好的方法如下。

#include <stdio.h>
#include <string.h>

int main()
{
    //Admin has 5 characters, and string requires one null terminator. So minimum length should be 6
    char username[10]; 
    int password,choice; 
    char Admin,i;

    printf("Welcome to the Students' Registration System\n");


    do
    {
        printf("Dear Registry employee: Kindly insert your username:\n");
        //Use %s to read a string completely(till white space character)
        scanf("%s", username);
        printf("Insert your password:\n");
        scanf("%d", &password);


        //You can't compare string using == or !=
    }while (strcmp(username, "admin") != 0 && password != 2016 );

    printf("The login process is successfully done");

    printf("Please choose the number of your next step:\n");
    printf("[1]Add new student\n");
    printf("[2]Add new course\n");
    printf("[3]Assign\remove courses for the student\n");
    printf("[4]Search and view students' details:\n");
    printf("[5]Request reports:\n"); 
    printf("[6]Update student/course record:\n");
    printf("[7]Delete student/course record:\n");

    return 0;
}