Stack(for mid term)

Stack(for mid term)

1. follows Last In First Out or First In Last Out

2. Stack class extends class Vector with five operations that allow a vector to be treated as a stack.

   • push(item)
     • Pushes an item onto the top of this stack
   • pop()
     • Removes the object at the top of this stack and returns that object as the value of this function.
     • throws EmptyStackException - if stack is empty.
   • peek()
     • Looks at the object at the top of this stack without removing it from the stack.
     • EmptyStackException - if this stack is empty.
   • empty()
     • true if and only if this stack contains no items; false otherwise.
   • search(object o)
     • the 1-based position from the top of the stack where the object is located; the return value -1 indicates that the object is not on the stack.
     • he topmost item on the stack is considered to be at distance 1

3. Constructor

   • Stack() ... Creates an empty Stack.

4. it also inherits many methods from class java.util.vector and java.lang.object

5. create stack

   • import java.util.stack package
     • Stack<E> stack = new Stack<E>();

6. print stack

   • System.out.println(stack);
     • elements are printed in order from bottom to top

7. exceptions

   • Underflow: Trying to pop/peek an element from an empty stack
   • Overflow: Trying to push an element into a stack that is already at its maximum capacity

8. parenthesis matching problem

   • mug up entire code
   • more topics in module

9. file versioning system

   • understand given code thoroughly

10. implementing stack

    • using Array, arraylist and linked list