structure
Interface Stack

All Superinterfaces:

Linear, Structure

All Known Implementing Classes:

AbstractStack, StackArray, StackList, StackVector

public interface Stack

extends Linear

An interface describing a Last-In, First-Out structure. Stacks are typically used to store the state of a recursively solved problem. The structure package provides several implementations of the Stack interface, each of which has its particular strengths and weaknesses.

Example usage:

To reverse a string using a stack, we would use the following:

 public static void main(String[] arguments)
 {
     if(arguments.length > 0){
	   Stack reverseStack = new StackList();
	   String s = arguments[0];
	    
	   for(int i=0; i < s.length(); i++){
	       reverseStack.push(new Character(s.charAt(i)));
	   }

	   while(!reverseStack.empty()){
	       System.out.print(reverseStack.pop());
	   }

	   System.out.println();
     }
 }
 

Method Summary

void	add(Object item) Add an element from the top of the stack.
boolean	empty() Returns true iff the stack is empty.
Object	get() Fetch a reference to the top element of the stack.
Object	getFirst() Fetch a reference to the top element of the stack.
Object	peek() Fetch a reference to the top element of the stack.
Object	pop() Remove an element from the top of the stack.
void	push(Object item) Add an element to top of stack.
Object	remove() Remove an element from the top of the stack.
int	size() Returns the number of elements in the stack.

Methods inherited from interface structure.Structure

clear, contains, elements, isEmpty, iterator, remove, values

Method Detail

add

public void add(Object item)

Add an element from the top of the stack.

Specified by:

add in interface Linear

Parameters:

item - The element to be added to the stack top.

Postcondition:

item is added to stack will be popped next if no intervening add

See Also:

push(java.lang.Object)

push

public void push(Object item)

Add an element to top of stack.

Parameters:

item - The value to be added to the top of the stack.

Postcondition:

item is added to stack will be popped next if no intervening push

remove

public Object remove()

Remove an element from the top of the stack.

Specified by:

remove in interface Linear

Precondition:

stack is not empty

Postcondition:

most recently added item is removed and returned

Returns:

The item removed from the top of the stack.

See Also:

pop()

pop

public Object pop()

Remove an element from the top of the stack.

Precondition:

stack is not empty

Postcondition:

most recently pushed item is removed and returned

Returns:

A reference to the removed element.

get

public Object get()

Fetch a reference to the top element of the stack.

Specified by:

get in interface Linear

Precondition:

stack is not empty

Postcondition:

top value (next to be popped) is returned

Returns:

A reference to the top element of the stack.

getFirst

public Object getFirst()

Fetch a reference to the top element of the stack.

Precondition:

stack is not empty

Postcondition:

top value (next to be popped) is returned

Returns:

A reference to the top element of the stack.

peek

public Object peek()

Fetch a reference to the top element of the stack.

Precondition:

stack is not empty

Postcondition:

top value (next to be popped) is returned

Returns:

A reference to the top element of the stack.

empty

public boolean empty()

Returns true iff the stack is empty. Provided for compatibility with java.util.Vector.empty.

Specified by:

empty in interface Linear

Postcondition:

returns true if and only if the stack is empty

Returns:

True iff the stack is empty.

size

public int size()

Returns the number of elements in the stack.

Specified by:

size in interface Linear

Postcondition:

returns the number of elements in the stack

Returns:

number of elements in stack.