Question

I get “Use of undeclared identifier ‘data'” when I compile that code. As you can see the problem is that add_student function can’t “see” student array.

What to do so to work properly ?

#include <stdio.h>

typedef struct {
    char *name;
    int  age;
    char *sex;
    int  class;
}student;


void add_student(int, char*, int, char*, int);

int main (int argc, const char * argv[])
{
    student data[5];

    add_student(5, "Mery", 3, "female", 8);
    return 0;
}

void add_student(int sequence, char *name, int age, char *sex, int class) {
    strcpy(data[sequence].name, name);
    data[sequence].age[13];
    strcpy(data[sequence].sex, sex);
    data[sequence].class[2];
}

Answer 1

The cleanest way to fix this is by passing data as an additional argument to add_student().

There are other errors, such as

1. passing 5 as the value of sequence and then using it to index into data;
2. the use of strcpy() is incorrect as you haven’t allocated memory for the name and sex fields;
3. the expressions data[sequence].age[13] and data[sequence].class[2] are not valid C.