在C中输入函数后出现printf（）错误

Question

Hi I am having an issue when I enter the AddEmployee() function.

When I enter I want it to print out "First Name" to prompt the user to enter the first name, but it prints out the following:

::Add Employee::
First Name:Last Name:

So instead of the first name being entered, instead when the user inputs it is actually the last name that is being scanned in.

How do I change the code so that it won't print out

First Name:Last Name:

But rather

First Name: (whatever user enters)
Last Name: (whatever user enters)

Here is the code I have written

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

struct Employee{

char FirstName[16];
char LastName[16];
char Address[21];
char ID[4];
char Duration[4];

};

void MainMenu();
void AddEmployee();


int main(int argc, char *argv[]) 
{
    MainMenu(); 
}


void MainMenu()
{   
    int main_menu = 0;

    printf("::Main Menu::\n");
    printf("1.) Add Employee:\n");
    scanf("%d", &main_menu);

    switch (main_menu) 
    {
        default:
        {
            printf("Invalid Choice!");
            break;
        }
        case(1):
        {
            AddEmployee();
            break;
        }
    }
}


void AddEmployee()
{   
    struct Employee employee;

    printf("::Add Employee::\n");
    printf("First Name:");
    fgets(employee.FirstName, 16, stdin);
    printf("Last Name:");
    fgets(employee.LastName, 16, stdin);

}

Answer 1

Use getchar() to clear the input buffer by reading the '\\n' left in buffer.

void AddEmployee()
{   
    struct Employee employee;

    printf("::Add Employee::\n");
    printf("First Name:");
    getchar();
    fgets(employee.FirstName, 16, stdin);
    printf("Last Name:");
    fgets(employee.LastName, 16, stdin);

}

You can add the getchar() even after the scanf() in main(),

 printf("::Main Menu::\n");
    printf("1.) Add Employee:\n");
    scanf("%d", &main_menu);
    getchar();
    switch (main_menu) 
    {
        default:
        {
            printf("Invalid Choice!");
            break;
        }
        case(1):
        {
            AddEmployee();
            break;
        }

and it is better to put getchar() right after the original scanf() in main() that resulted in left over \\n in buffer, considering the comment by @Mike.