Variable Scope

• memory allocated on stack gets freed when a function returns
• variable scope: all variables defined in functions disappear when the function returns
• memory allocated on the heap “dynamically” are not freed when the function returns
• if you dynamically allocate memory, you have to free that by yourself

Pointers

• are data types that store a memory address of another variable
• the pointer itself is actually stored on the stack

int x;
int* p;

x = 7;
p = Null;
p = &x;

cout << *p << endl;
cout << p << endl;

Dynamic Memory Allocation

malloc from C becomes new in C++

int* p = new int;

free from C becomes delete in C++

delete p;

Destructors

Updating our student class from last time.

class student{
	private:
		string name;
		int* grade;
	public:
		student();
		student(int);
}

student:student(){
	name = "";
	grade = NULL;
}

student::student(int n){
	grade = new int[n];
}

int main(){
	student x(10);
	return 0;
}

Question: we just returned and exited the program, but our memory on the heap is still out there. How can we solve this?