net.datastructures

Interface Stack<E>

All Known Implementing Classes:

ArrayStack, NodeStack

public interface Stack<E>

Interface for a stack: a collection of objects that are inserted and removed according to the last-in first-out principle. This interface includes the main methods of java.util.Stack.

See Also:

EmptyStackException

Method Summary

Modifier and Type	Method and Description
boolean	isEmpty() Return whether the stack is empty.
E	pop() Remove the top element from the stack.
void	push(E element) Insert an element at the top of the stack.
int	size() Return the number of elements in the stack.
E	top() Inspect the element at the top of the stack.

Method Detail

isEmpty

boolean isEmpty()

Return whether the stack is empty.

Returns:

true if the stack is empty, false otherwise.

pop

E pop()
throws EmptyStackException

Remove the top element from the stack.

Returns:

element removed.

Throws:

EmptyStackException - if the stack is empty.

push

void push(E element)

Insert an element at the top of the stack.

Parameters:

element - to be inserted.

size

int size()

Return the number of elements in the stack.

Returns:

number of elements in the stack.

top

E top()
throws EmptyStackException

Inspect the element at the top of the stack.

Returns:

top element in the stack.

Throws:

EmptyStackException - if the stack is empty.