expected ) and ( error in c - c

Question

while compiling i am having an error: expected ) and ( in c for the following program:
#include<stdio.h>
#include<conio.h>
struct student
{
char name[20];
int rollno;
int age;
char classes[10];
};
void printdata(struct student &sob); //getting error in this line
void main()
{
struct student stud;
clrscr();
printf("enter student details:");
printf("\nenter student name:"); fflush(stdin);
gets(stud.name);
printf("\nenter age:");
scanf("%d",&stud.age);
printf("\nenter rollno:");
scanf("%d",&stud.rollno);
printf("\nenter class of student:"); fflush(stdin);
gets(stud.claases);
printdata( &stud);
getch();
}
void printdata(struct student &sob) //getting error in this line
{
struct student *ptr;
ptr=sob;
printf("student details are as follows:");
printf("\nstudent's name:"); fflush(stdout);
puts(ptr->name);
printf("\n student' age:%d",ptr->age);
printf("\n student's roll no:%d",ptr->rollno);
printf("\n student's class:"); fflush(stdout);
puts(ptr->classes);
}
it is that i have already declared the structure student then why is it giving me the error ( and ) in two lines..

Answer 1

struct student & is not valid C. It appears to be C++ code.
void main() is not valid C (unless the program is a free standing one, which this one clearly is not).
The gets() function has been removed from the C language as per the C11 standard.
fflush(stdin) is undefined behavior.
Unrelated, your code is difficult to read. Make a habit of adding some empty lines between different functions and declarations.
Unrelated, it appears that you are using Turbo C for DOS or something equally bad and non-standard. Don't use such old crap compilers, using a bad compiler is one source for all these problems.

Answer 2

You made a typo :
gets(std.claases); // it's std.classes
And the printdata() param should be "struct student *sob".
This solution should works :
#include <stdio.h>
struct student {
char name[20];
int rollno;
int age;
char classes[10];
};
void printdata(struct student *sob);
int main(void) {
struct student stud;
printf("enter student details:");
printf("\nenter student name:");
fflush(stdin);
gets(stud.name);
printf("\nenter age:");
scanf("%d", &stud.age);
printf("\nenter rollno:");
scanf("%d", &stud.rollno);
printf("\nenter class of student:");
fflush(stdin);
gets(stud.classes);
printdata(&stud);
return 0;
}
void printdata(struct student *sob)
{
struct student *ptr;
ptr = sob;
printf("student details are as follows:");
printf("\nstudent's name:");
fflush(stdout);
puts(ptr->name);
printf("\n student' age:%d", ptr->age);
printf("\n student's roll no:%d", ptr->rollno);
printf("\n student's class:");
fflush(stdout);
puts(ptr->classes);
}
BTW, the main function must return an integer, it's a standard.

Answer 3

Your function printData should accept a pointer struct student *ob not struct student &ob.

Answer 4

There's no reference in C (like in C++). Change the function prototype and defintion to take pointers as argument.
Change
void printdata(struct student &sob); //getting error in this line
to
void printdata(struct student *sob); //getting error in this line
and change
void printdata(struct student &sob) //getting error in this line
to
void printdata(struct student *sob) //getting error in this line
Other problems are:
You have misspelled a member name: gets(stud.claases); should be: gets(stud.classes);
Don't use gets(). Use fgets() instead as gets() isn unsafe and cause buffer overflow issue.
fflush(stdin); is undefined behaviour in C.