21

java.util

THE PACKAGE JAVA.UTIL

The classes

Vector

 and

Stack

 are simple container classes that provide

extensions to the capabilities of Java arrays. A

Vector

, unlike a Java array, can

change its size, and many convenient methods are provided for adding, removing,

and searching for items. A

Stack

 is a

Vector

 with additional operations such as

push

 and

pop

.

The hierarchy of classes defined in package

java.util

 is as follows. (Classes

whose names are shown here in

boldface

 are in package

java.util

; the others

are in package

java.lang

 and are shown here to clarify subclass relationships.)

Object

 20.1

interface Enumeration

 21.1

BitSet

 21.2

Date

 21.3

Dictionary

 21.4

Hashtable

 21.5

Properties

 21.6

Observable

 21.7

interface Observer

 21.8

Random

 21.9

StringTokenizer

 21.10

Vector

 21.11

Stack

 21.12

Throwable

 20.22

Exception

RuntimeException

EmptyStackException

 21.13

NoSuchElementException

 21.14

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