stack implementation using array push pop operations in stack cpp c++ program

 #include<iostream>
using namespace std;
int stack[100];
int n,i,top,x;
void push();
void pop();
void display();
int main()
{
  int ch;
  cout<<"Enter the number of elements in the stack";
  cin>>n;
  i=1;
  top=-1;
  while(i)
  { cout<<"Enter your choice (1-4)"<<endl;
    cout<<"1.PUSH\n2.POP\n3.DISPLAY\n4.EXIT\n";
    cin>>ch;
    switch(ch)
    {
      case 1:push();
             break;
      case 2:pop();
             break;
      case 3:display();
             break;
      case 4:i=0;
             break;
      default:cout<<"Wrong Choice!!!!"<<endl;
             break;
    }
  }
return 0;
}
void push()
{
    if(top>=n-1)           // OVERFLOW i.e. if stack top goes beyond the size of the stack
    {
      cout<<"STACK IS OVERFLOW"<<endl;

  }
  else
  {

    cout<<"Enter the value to be added :";
  cin>>x;
  top=top+1;
  stack[top]=x;
    }
}
void pop()
{
  if(top<=-1)                // Underflow i.e. stack is at index -1
  {
    cout<<"STACK IS UNDERFLOW"<<endl;
  }
  else
  {
    cout<<"Value :"<<stack[top]<<"GOT deleted."<<endl;
    top--;
  }
}
void display()
{
  if(top>=0)
  {
    cout<<"Elements in the stack are :";
    for(i=top;i>=0;i--)
       cout<<stack[i]<<" ";
    cout<<"\n";
  }
  else
   cout<<"STACK IS EMPTY."<<endl;
}