Added in API level 1

Stack

open class Stack<E : Any!> : Vector<E>
kotlin.Any
   ↳ java.util.AbstractCollection<E>
   ↳ java.util.AbstractList<E>
   ↳ java.util.Vector<E>
   ↳ java.util.Stack

The Stack class represents a last-in-first-out (LIFO) stack of objects. It extends class Vector with five operations that allow a vector to be treated as a stack. The usual push and pop operations are provided, as well as a method to peek at the top item on the stack, a method to test for whether the stack is empty, and a method to search the stack for an item and discover how far it is from the top.

When a stack is first created, it contains no items.

A more complete and consistent set of LIFO stack operations is provided by the Deque interface and its implementations, which should be used in preference to this class. For example:

<code>Deque&lt;Integer&gt; stack = new ArrayDeque&lt;Integer&gt;();</code>

Summary

Public constructors

Creates an empty Stack.

Public methods
open Boolean

Tests if this stack is empty.

open E

Looks at the object at the top of this stack without removing it from the stack.

open E
pop()

Removes the object at the top of this stack and returns that object as the value of this function.

open E
push(item: E)

Pushes an item onto the top of this stack.

open Int
search(o: Any!)

Returns the 1-based position where an object is on this stack.

Inherited functions
Inherited properties

Public constructors

Stack

Added in API level 1
Stack()

Creates an empty Stack.

Public methods

empty

Added in API level 1
open fun empty(): Boolean

Tests if this stack is empty.

Return
Boolean true if and only if this stack contains no items; false otherwise.

peek

Added in API level 1
open fun peek(): E

Looks at the object at the top of this stack without removing it from the stack.

Return
E the object at the top of this stack (the last item of the Vector object).
Exceptions
java.util.EmptyStackException if this stack is empty.

pop

Added in API level 1
open fun pop(): E

Removes the object at the top of this stack and returns that object as the value of this function.

Return
E The object at the top of this stack (the last item of the Vector object).
Exceptions
java.util.EmptyStackException if this stack is empty.

push

Added in API level 1
open fun push(item: E): E

Pushes an item onto the top of this stack. This has exactly the same effect as:

addElement(item)

Parameters
item E: the item to be pushed onto this stack.
Return
E the item argument.
Added in API level 1
open fun search(o: Any!): Int

Returns the 1-based position where an object is on this stack. If the object o occurs as an item in this stack, this method returns the distance from the top of the stack of the occurrence nearest the top of the stack; the topmost item on the stack is considered to be at distance 1. The equals method is used to compare o to the items in this stack.

Parameters
o Any!: the desired object.
Return
Int 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.