My question is pretty simple, I just want to know how to call my operator== function in Stack.cpp using a list function. Here is what I meant. This is my Stack.h file: class Stack { public: /**constructors and destructors*/ Stack(); Stack(const Stack &S); ~Stack(); void pop(); void push(int data); bool operator==(const Stack &S); [ .......] private: List stack; }; Here is my List.h file: template class List { private: struct Node { listitem data; Node* next; Node* previous; Node(listitem data) : next(NULL), previous(NULL), data(data) { } }; typedef struct Node* NodePtr; NodePtr start; NodePtr end; NodePtr cursor; int length; public: ........ bool operator==(const List &list); [.......] } [........] template bool List::operator==(const List& list) { if (length != list.length) return false; NodePtr temp1 = start; NodePtr temp2 = list.start; while (temp1 != NULL) { if (temp1->data != temp2->data) return false; temp1 = temp1->next; temp2 = temp2->next; } return true; } [......] So I already define my functions in List.h and I only need to call my function from List again in my Stack.cpp file. For example from my Stack.cpp: Stack::Stack(const Stack &S) : stack(S.stack) { } void Stack::pop() { stack.remove_start(); } [......] And I don\'t know how to call my operator== function in Stack.cpp from the List.h like the way above. This is what my guess so far but did not work: bool Stack::operator==(const Stack &S) { stack.operator==(S.stack); } Thank you Solution When we wish to make a comparison, such as in an if statement, we use the double equals sign (==). 1)bool operator==(const Stack &S); [ .......] It means whatever the boolean operator it should be belongs to stack or equal to. 2) bool operator==(const List &list); Likewise link list also compare with the constructor link list. and constructor need not to call explicitly. it will call itself when program called first..

1. My question is pretty simple, I just want to know how to call my operator== function in
Stack.cpp using a list function.
Here is what I meant. This is my Stack.h file:
class Stack {
public:
/**constructors and destructors*/
Stack();
Stack(const Stack &S);
~Stack();
void pop();
void push(int data);
bool operator==(const Stack &S);
[ .......]
private:
List stack;
};
Here is my List.h file:
template
class List {
private:
struct Node {
listitem data;
Node* next;
Node* previous;
Node(listitem data) :
next(NULL), previous(NULL), data(data) {
}
};
typedef struct Node* NodePtr;
NodePtr start;
NodePtr end;
NodePtr cursor;
int length;
public:
........

2. bool operator==(const List &list);
[.......] }
[........]
template
bool List::operator==(const List& list) {
if (length != list.length)
return false;
NodePtr temp1 = start;
NodePtr temp2 = list.start;
while (temp1 != NULL) {
if (temp1->data != temp2->data)
return false;
temp1 = temp1->next;
temp2 = temp2->next;
}
return true;
}
[......]
So I already define my functions in List.h and I only need to call my function from List again in
my Stack.cpp file. For example from my Stack.cpp:
Stack::Stack(const Stack &S) :
stack(S.stack) {
}
void Stack::pop() {
stack.remove_start();
}
[......]
And I don't know how to call my operator== function in Stack.cpp from the List.h like the way
above. This is what my guess so far but did not work:
bool Stack::operator==(const Stack &S) {
stack.operator==(S.stack);
}
Thank you
Solution

3. When we wish to make a comparison, such as in an if statement, we use the double equals sign
(==).
1)bool operator==(const Stack &S); [ .......]
It means whatever the boolean operator it should be belongs to stack or equal to.
2) bool operator==(const List &list);
Likewise link list also compare with the constructor link list.
and constructor need not to call explicitly. it will call itself when program called first.