Noob - Program Keeps Crashing

[icu222much]

I am trying to create a program where it will read in the student name, nationality, and grades, and calculate their tuition fee based on those information.

I began to write a bit of code by I have ran into some problems. When I try to run my code, the compiler says "warning C4700: local variable 'name' used without having been initialized" but continues to run the code. Then the program shuts down. What is happening?

In addition, on my fifth line I have "char *firstName;". I know that char* represents a pointer, but what does that mean and why can't I just use a string?

#include <iostream>
using namespace std;

struct Student {
	char *firstName;
	char *lastName;
	bool canadianship;
	int grades[10];
};

Student newStudent[10];

void addFirstName() {
	char *name;
	cout << "Student Name: ";
	cin >> name;
	newStudent[0].firstName = name;
}


int main() {
	addFirstName();
	cout << newStudent[0].firstName;	
	return 0;
}

[tabstop]

You can just use a string. In fact for your program to have any hope of working, you must use a string. In order to use a string, you do have to bring in the string library with #include <string>.

[icu222much]

Thank you for the quick reply. How about why my program keeps crashing?

[mramazing]

You need to allocate space for you pointers... char *name is only a pointer. You need to allocate the memory for the names...

void addFirstName() {
	char *name = new char[64];
	cout << "Student Name: ";
	cin >> name;
	newStudent[0].firstName = name;
}

That should fix the problem

[tabstop]

Thank you for the quick reply. How about why my program keeps crashing?

Because you seem to think "string" is spelled "char *"?

[icu222much]

Thank you.

Sorry, i thought char * was just another way of declaring a string.

[Daved]

>> Sorry, i thought char * was just another way of declaring a string.

It is. Well, sort of.

Using char* for strings is the C way of doing it, but it works in C++ and is still used by many tutorials/books/instructors. Using the C++ string class is generally preferred in C++, so if you can use that, do it.

If you can't, then you need to allocate space for your char* string. An easy solution is to use a plain char array instead of just a pointer. Then you can allocate space for the string by setting the number of characters in the array. That restricts to a maximum string size, though. Another solution is to use a dynamic array allocated with new[] and destroyed with delete[]. If you're going to do that, though, you really should just use the string class.

[icu222much]

Gotcha! Thank you.