错误：无法将参数1从'char [80]'转换为'char'

Question

我正在尝试将int传递给结构体。我必须验证它，类指令说我必须通过函数运行它。

以下是错误消息：

C2664: 'int get_id(char)' : cannot convert argument 1 from 'char [80]' to 'char'

 #define _CRT_SECURE_NO_WARNINGS
    #include <stdio.h>
    #include <conio.h>
    #include <stdlib.h>
    #include <cstdio>
    #include <iostream>
    #include <fstream>
    #include <cstring>
    #include <exception>


//functions called
int get_id(char);

//structs
struct fileinfo
{
    int id;
    char name[20];
    char state[5];
    char dis_code;
    float balance;
    char due_date[40];
};


//why is it void?
int main(void)
{
    fileinfo info[80];

    int ct = 0;
    char more = 'y';
    char buff[80];

    while (more == 'y')
    {

        printf("ID: ");
        gets_s(buff);

        info[ct].id = get_id(buff);
        printf("this is ID: %i", info[ct].id);

        printf("Do you want to enter another? ");
        gets_s(buff);
        more = buff[0];
    }

    system("pause");

}//end main

int get_id(char buf[])
{
    int id;
    char buffer[85];
    bool check = false;

    id = atoi(buf);
    while (check == false)
    {
        if (id > 998)
        {
            printf("\n This ID number is too large, please re-enter: ");
            gets_s(buffer);
            id = atoi(buffer);
            check = false;
        }
        else
        {
            check = true;
        }
    }

    return id;
}