Structures help

[kabuki]

In this program, I just want to input an employee's data and then have it show me the report. My question is what am I doing wrong here because I'm not getting the right report. I think that I have to do something with pointers to a structure but I'm confused with the -> operator, the . operator, and the * operator.

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


typedef struct EmpInfo
{
    char firstname[10+1],lastname[15+1],fullname[25+1];
    float payrate, hours, defr;
}EmpRecord;

void InputEmpData(EmpInfo theEmps);
void DispalyData(EmpInfo theEmps);
int main(void)
{
    EmpInfo theEmps;
    InputEmpData(theEmps);
    DispalyData(theEmps);
    fflush(stdin);
    getchar();
    return 0;
}

void InputEmpData(EmpInfo theEmps)
{
	printf("Enter employee's first name: ");
	scanf("%s",theEmps.firstname);
	printf("Enter employee's last name: ");
	scanf("%s",theEmps.lastname);
	printf("Enter hourly payrate: ");
	scanf("%f",&theEmps.payrate);
	printf("Enter hours worked this pay peroid: ");
	scanf("%f",&theEmps.hours);
	printf("Enter deferred amount:");
	scanf("%f",&theEmps.defr);
	strcpy(theEmps.fullname,theEmps.lastname);
	strcat(theEmps.fullname,", ");
	strcat(theEmps.fullname,theEmps.firstname);
}
void DispalyData(EmpInfo theEmps)
{
     printf("%c\n Name: ",theEmps.fullname);
     printf("%f\n Payrate:",theEmps.payrate);
     printf("%f\n Hours: ",theEmps.hours);
     printf("%f\n Deferred: ",theEmps.defr);      
}

[Zhuge]

Your input data function doesn't actually do anything of any use because it operates on a copy that is thrown away when the function ends. Try passing its parameter by reference.

[kabuki]

That's what I don't understand about structures, do I pass the members of the struct by reference or do I pass the struct variable by reference?

[Peter87]

I think that I have to do something with pointers to a structure but I'm confused with the -> operator, the . operator, and the * operator.

If p is a pointer you write *p to get what p points to. If p is a pointer to a struct object you you can access the members of that object using the dot operator like normal (*p).member. As a shorthand for this syntax you can use the -> operator p->member. Both way means the same.

That's what I don't understand about structures, do I pass the members of the struct by reference or do I pass the struct variable by reference?

Both are possible but it probably makes more sense to pass the struct object.

[kabuki]

Thanks for directing me to the right direction, I've fixed it.

[kabuki]

Now, I'm having trouble again with this code. This time, I tried to use an array of structures but it keeps saying that there is a linker error. Can you please point out my error to me?

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


typedef struct EmpInfo
{
    char firstname[10+1],lastname[15+1],fullname[25+1];
    float payrate,hours, defr;
}EmpInfo;

void InputEmpData(EmpInfo theEmps[3]);
void DispalyData(EmpInfo theEmps[3]);
int main(void)
{
    EmpInfo theEmps[3];
    InputEmpData(&theEmps[3]);
    DispalyData(&theEmps[3]);
    fflush(stdin);
    getchar();
    return 0;
}

void InputEmpData(EmpInfo *theEmps[3])
{
    for (int count = 0;count<3;count++)
    {
	printf("Enter employee's first name: ");
	scanf("%s",theEmps[count]->firstname);
	printf("Enter employee's last name: ");
	scanf("%s",theEmps[count]->lastname);
	printf("Enter hourly payrate: ");
	scanf("%f",&theEmps[count]->payrate);
	printf("Enter hours worked this pay peroid: ");
	scanf("%f",&theEmps[count]->hours);
	printf("Enter deferred amount:");
	scanf("%f",&theEmps[count]->defr);
	strcpy(theEmps[count]->fullname,theEmps[count]->lastname);
	strcat(theEmps[count]->fullname,", ");
	strcat(theEmps[count]->fullname,theEmps[count]->firstname);
    }
}
void DispalyData(EmpInfo theEmps[3])
{
         for(int count = 0;count<3;count++)
    {
     printf(" Name: %s\n",theEmps[count].fullname);
     printf(" Payrate: %f\n",theEmps[count].payrate);
     printf(" Hours: %f\n",theEmps[count].hours);
     printf(" Deferred: %f\n",theEmps[count].defr);      
}}

[Peter87]

You have declared InputEmpData as
void InputEmpData(EmpInfo theEmps[3]);
but when you define it you have added a * which makes the parameter a different type and the function a different function.
void InputEmpData(EmpInfo *theEmps[3])

[kabuki]

I've just removed the * from

void InputEmpData(EmpInfo *theEmps[3])

and now I'm getting errors from my -> operators saying

base operand of `->' has non-pointer type `EmpInfo'

[kabuki]

Okay, I've just fixed it. I just changed all the operators to . operator but now I'm getting semantic errors.