Runtime Check #3 variable used not defined - Structs pointer error

Hi,
I am fairly new to programming using structs in C and I get the following when trying to assign a value to a member variable of type struct. Any inputs on getting this addressed will be much appreciated.

Here is the code for the program I am using:

Code:

---

int _tmain(int argc, _TCHAR* argv[])
{
        struct employee {
                char name[30];
                int emp_id;
                float salary;
        };
                struct employee *emp2;
        emp2->emp_id = 3456; // error occurs here
        return 0;

}

---

The specific error message is Run-TIme Check Failure #3 - The variable emp2 is being used without being defined.

Thanks,
Manisha

Code:

---

struct employee *emp2;
emp2->emp_id = 3456; // error occurs here

---

Where does emp2 point to? As a pointer it must point to a valid memory location. Currently it is an uninitialized pointer with some random value.

http://cboard.cprogramming.com/cplus...ead-first.html
SourceForge.net: Common mistakes and errors - cpwiki

You created the structure variable as a pointer. As a pointer it must point to a valid memory location
You didn't assign any address to that pointer variable. So that you got an error.

Try this,

Code:

---

struct employee *emp2;
emp2=(struct employee *) malloc(sizeof(struct employee));
emp2->emp_id = 3456;          // problem solved

---

you do not need cast malloc in C - see FAQ

Quote:

---

Originally Posted by abinila

You created the structure variable as a pointer. As a pointer it must point to a valid memory location
You didn't assign any address to that pointer variable. So that you got an error.

Try this,

Code:

---

struct employee *emp2;
emp2=(struct employee *) malloc(sizeof(struct employee));
emp2->emp_id = 3456;          // problem solved

---

---

I would urge you, and the OP, to read the links posted, because it covers exactly why it doesn't work and what you just typed out in vain now.