STACKS

  Stacks are a restricted insert and remove data structure:

  Specifically - LIFO

  Stacks are really great for expression resolution

  Classicaly stack has three functions:

     void push (T element) //insert
     T pop() //remove and return
     T top() //look at the top element

  For aiding poor programmers:

     Boolean isEmpty()

  Java Methods:

     Everything Collection
     Everything in List

     boolean empty() //isEmpty method
     T peek()        //top()
     T pop()
     T push(T item) 

  What if I only have a LinkedList?
     LinkedList j;
     j.addLast(element) // push
     j.removeLast() // pop
     j.get(j.size-1) // top

     - or -

     j.addFirst(element)
     j.removeFirst()
     j.get(0)

  public class genericPerson<AnyType extends Person>{
   ...
  }

  public interface myinterface{
   
    public int add(int a, int b);

  }
 
  public class myclass implements myinterface{

    public int add(int a, int b){
     return a+b;
    }

    private int add(int a, int b, int c){
     return a+b+c;
    }
  }