How can I stop my integers from displaying as HEX? - c++

Question

I am practicing some code implementing different data structures. For this example I am trying to implement a simple stack data structure. So far it works as intended, but I keep getting Hex characters when trying to display my stack. Could anyone help me with figuring out why this is the case?
Also I am trying to get better at structuring my code properly, can anyone that is already involved in the industry please give me some constructive criticism as to what I have coded so far. Thanks.
#include <iostream>
using namespace std;
// stack_MAX == maximum height of stack
const int stack_MAX = 10;
class stack{
public:
stack(){
//Constructor initializes top of stack
top = -1;
}
bool isFull(int top){
//isFull() will check to make sure stack is not full
//Will return TRUE if stack is FULL, and FALSE if
//stack is NOT FULL
if(top == stack_MAX - 1)
return true;
else
return false;
}
bool isEmpty(int top){
//isEmpty() will check to make sure stack is not empty
//Will return TRUE if stack is EMPTY, and FALSE if
//stack is NOT EMPTY
if(top == -1)
return true;
else
return false;
}
void push(int x){
//push() will push new element on top of stack
if(isFull(top)){
cout << "Sorry, but the stack is full!" << endl;
exit(1);
}
else{
top++;
x = stk[top];
}
}
void pop(){
//pop() will pop the top element from the stack
if(isEmpty(top)){
cout << "Sorry, but the stack is empty!" << endl;
exit(1);
}
else{
cout << stk[top] << " is being popped from stack!" << endl;
top--;
}
}
void display_stack(){
//diplay_stack() will show all elements currently in the stack
int temp; //will temporarily hold position of stack
temp = top;
while(!isEmpty(temp)){
cout << stk[temp] << endl;
temp--;
}
}
private:
int top;
int stk[stack_MAX];
};
int menu(){
int choice;
cout << "Welcome to my stack!" << endl;
cout << "What would you like to do? (select corresponding #)" << endl << endl;
cout << "1. Push" << endl;
cout << "2. Pop" << endl;
cout << "3. Display" << endl;
cout << "4. Quit" << endl;
cin >> choice;
return choice;
}
int main()
{
int selection, x;
stack myStack;
selection = menu();
while(selection != 4)
{
switch(selection){
case 1:
cout << "please enter number to be pushed: ";
cin >> x;
myStack.push(x);
selection = menu();
break;
case 2:
myStack.pop();
selection = menu();
break;
case 3:
myStack.display_stack();
selection = menu();
break;
default:
cout << "Oops that's not a selection, try again" << endl;
selection = menu();
break;
}
}
cout << "Thank you for stopping by and using my stack!" << endl;
system("pause");
return 0;
}

Answer 1

A statement in your push functin is wrong, modified as below:
void push(int x)
{
//push() will push new element on top of stack
if(isFull(top))
{
cout << "Sorry, but the stack is full!" << endl;
exit(1);
}
else
{
top++;
/***************************
x = stk[top];
****************************/
stk[top] = x;
}
}
Advice:
Learn to debug, here is the tutorial
Include the head file cstdlib when you want to use exit in your
code
Do not name your class with the same name for any classes in STL

Answer 2

As pointed out by prehistoric penguin, your push() function is incorrect:
x = stk[top];
Should be changed to:
stk[top] = x;
I wanted to comment anyway to offer some general comments as you requested:
If statements like this can be replaced by a single line of code:
if(top == stack_MAX - 1)
return true;
else
return false;
becomes:
return (stack_MAX - 1 == top);
Put constant expressions on the left-hand side of your comparison expression. For example:
(top == stack_MAX - 1)
becomes:
(stack_MAX - 1 == top)
The reason is that one day you will accidentally type something like:
(top = stack_MAX - 1)
and you or somebody else will waste a lot of time debugging it :)
Your isFull() and isEmpty() functions shouldn't take a parameter. They should just use the private member variable top. How would somebody call these functions without access to top, which you've correctly made a private member?
In general, avoid using. In my opinion it defeats the whole purpose of namespaces. using namespace std is a commonly used exception, but even then, is it so hard to type std::cout?
Always put curly braces around the clauses of your if statement, even if they are just one line. It's easy to forget to add braces if you need to add more statements to a clause later on, which can be quite confusing.
Your code formatting is pretty good, but pick a bracket style and be consistent. Either always put the opening curly brace on the same line as the function header / control statements etc, or always put it on the line afterwards.
Hope that helps.