Error: Array type has incomplete element type and binary operand error

Question

I am trying to make a multi-program database in C.

Here is the code:

#include<stdio.h>
#include<stdlib.h>
#include "function.c"


int main()
{
info();
example();

printf("\n\n\n");

char name[1][10], id[1][10], grade[1][1];
char choice;
int x=0;
int sal[1];
FILE *fp;

printf("Would you like to continue? Y/N: ");
scanf("%c",&choice);
fflush(stdin);

if(choice == 'Y' || choice == 'y')
{
    system("cls");

    fp = fopen("database.txt","w");

    if(fp == NULL)
    {
        printf("File does not exist!");
        return 0;
    }
    else
    {
        while(x<=1)
        {
            printf("Enter Employee name no.%d: ",(x+1));
            scanf("%s",name[x]);
            fprintf(fp, "Employee Name: %s\n",name);

            printf("Enter Employee ID: ");
            scanf("%s",id[x]);
            fprintf(fp, "Employee ID: %s\n",id);

            printf("Enter Employee Grade Level (A-E): ");
            scanf("%s",grade[x]);
            fprintf(fp, "Employee Grade Level: %s\n",grade);

            printf("Enter Employee's Basic Salary: ");
            scanf("%d",&sal[x]);
            fprintf(fp, "Employee's Basic Salary: %d\n\n\n",sal);

            printf("Employee's bonus: %d\n",bonus(grade[x],sal[x]));

            printf("Employee's allowance: %d\n",allowance(grade[x], sal[x]));

            printf("\n");
        }
    }   
    fclose(fp);
}
else
{
    return 0;
}




return 0;
}

function.c :

#include<stdio.h>
#include "function.h"

int bonus(char *grade[1][], int *sal[])
{
int bonus;
int *b;
int x;

b = &bonus;

for(x=0;x<=1;x++)
{

    switch(*grade[x])
    {
        case 'A':
            bonus = (1/4) * *sal[x];
            break;
        case 'B':
            bonus = (1/5) * *sal[x];
            break;
        case 'C':
            bonus = (15/100) * *sal[x];
            break;
        case 'D':
            bonus = (1/10) * *sal[x];
            break;
        case 'E':
            bonus = (5/100) * *sal[x];
            break;
        default:
            printf("Invalid Choice!!");
            break;
    }

    return bonus;
    }
}

int allowance(char *grade[1][], int *sal[])
{
int all;
int *a;
int x;

a = &all;

for(x=0;x<=1;x++)
{
    switch(*grade[x])
    {
    case 'A':
        all = (3/10) * *sal[x];
        break;
    case 'B':
        all = (6/25) * *sal[x];
        break;
    case 'C':
        all = (9/50) * *sal[x];
        break;
    case 'D':
        all = (3/25) * *sal[x];
        break;
    case 'E':
        all = (3/50) * *sal[x];
        break;
    default:
        printf("Invalid Choice!!");
        break;
    }

    return all;
    }

}

function.h:

#ifndef _FUNCTION_H_INCLUDED
#define _FUNCTION_H_INCLUDED

int bonus(char *grade[][], int *sal[]); //prototype for calculating bonus
int allowance(char *grade[][], int *sal[]); //prototype for allowance
void info(); //prototype for information
void example(); //prototype for example

#endif

When I try to compile the program, I get:

2   0   function.c  In file included from function.c
4   17  function.h  [Error] array type has incomplete element type
5   21  function.h  [Error] array type has incomplete element type
4   17  function.c  [Error] array type has incomplete element type
function.c  In function 'bonus':
18  19  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')
21  19  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')
24  22  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')
27  20  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')
30  21  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')
function.c  At top level:
41  21  function.c  [Error] array type has incomplete element type
function.c  In function 'allowance':
54  17  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')
57  17  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')
60  17  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')
63  17  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')
66  17  function.c  [Error] invalid operands to binary * (have 'int' and 'int *')

I do not know what the problem is (I'm a beginner in C programming).

My first question: What does array type has incomplete element type mean? Next question: Why am I still getting the invalid operands to binary * error?

Any help would be appreciated.

Answer 1

In the declarations in function.h, you have:

int bonus(char *grade[][], int *sal[]);

You can't leave out all the dimensions; you have to specify a number for every dimension of an array except, perhaps, the first. For example, this might be legitimate:

int bonus(char *grade[][20], int *sal[]);

I've not checked whether 20 is the appropriate number, but some number must be used in the context.

This is causing the 'incomplete array type' message.

Answer 2

for "My first question: What does array type has incomplete element type mean?"

this error occur because in c language you need to specify the array size if you are not declaring it like

int arr[] = {6,1,2,3};

otherwise

it should be int arr[<size of the array>];

for invalid operands to binary * error?

it occurs because you are trying to multiply int and int * values

consider seeing this http://forums.devshed.com/c-programming-42/dynamic-arrays-with-undeclared-size-62036.html

and read some more tutorials about pointers and arrays and how to mix them