This is a simple Java program to demonstrate the Stack data structure implementation. This code provides a simple implementation of a stack with basic operations (push, pop, and isEmpty). Understanding how a stack works is fundamental, and this code demonstrates the concept in a straightforward manner. Additionally, it introduces the concept of an inner class (Node), which is commonly used in data structure implementations. Internally, the stack is implemented as a linked list.

push Method:

  • The push method is used to add a new item to the top of the stack.
  • It creates a new node (newTop) and assigns the value N to its item field.
  • The next field of the new node is set to the current top of the stack.
  • Finally, the top reference is updated to the new node.

pop Method:

  • The pop method removes the top item from the stack and returns its value.
  • It first retrieves the value of the top item (topItem), updates the top reference to the next node in the stack, and then returns the retrieved value.
  • Note: This method does not handle the case where an attempt is made to pop from an empty stack. It would be better to throw a specific exception in that case.