In JDK 1.5, ENUM has two types, enumset and enummap
Example 1. Demo.java
Package maoxiang.examples.jdk15.enum;
Import java.util.enumset;
/ **
* @Author Mao Xiang
*
* Enumset
* Enummap
*
* /
Public class demo {
ENUM DAY {Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday}
Public static void main (String [] args) {
Demo demo = new demo ();
Demo.test1 ();
}
Public void test1 () {
For (Day D: enumset.Range (day.monday, day.friday))
System.out.println (d);
}
}
Example 2. Card.java
Package maoxiang.examples.jdk15.enum;
Import java.util.arraylist;
Import java.util.list;
/ **
* @Author Mao Xiang
*
* /
PUBLIC Class Card {
Public Enum Rank {deuce, Three, Four, Five, Six,
Seven, Eight, Nine, Ten, Jack, Queen, King, ACE}
Public Enum Suit {Clubs, Diamonds, Hearts, Spades}
PRIVATE FINAL RANK RANK;
PRIVATE FINAL SUIT;
Private card (rank rank, suit suit) {
THIS.RANK = Rank;
THIS.SUIT = SUIT;
}
Public Rank Rank () {RETURN RANK;}
Public suit suit () {return suit;}
Public string toString () {Return Rank "of" suit;
Private static final list
// Initialize Prototype Deck
STATIC {
Suit suit: suit.values ())
For (Rank Rank: rank.values ())
Protodeck.Add (New Card (Rank, Suit);
}
Public static arraylist
Return New ArrayList
}
}
Example 3. Howeration.java
Package maoxiang.examples.jdk15.enum;
Public enum operation {
Plus {Double Eval (Double X, Double Y) {Return X Y;}},
Minus {Double Eval (Double X, Double Y) {Return X - Y;}},
Times {Double Eval (double x, double y) {return x * y;}},
Divide {Double Eval (double x, double y) {return x / y;}}; // do arithmetic op reported by this constant
Abstract Double Eval (Double X, Double Y);
Public static void main (string args []) {
Double x = double.parsedouble (args [0]);
Double y = double.parsedouble (args [1]);
For (Operation Op: Operation.Values ())
System.out.printf ("% f% S% f =% f% N", x, op, y, op.eval (x, y));
}
}
Example 4 Planet.java
Package maoxiang.examples.jdk15.enum;
/ **
* @Author Mao Xiang
*
* /
Public enum planet {
Mercury (3.303e 23, 2.4397e6),
Venus (4.869e 24, 6.0518e6),
Earth (5.976e 24, 6.37814e6),
Mars
(6.421E 23, 3.3972E6),
Jupiter (1.9e 27, 7.1492e7),
Saturn (5.688E 26, 6.0268E7),
Uranus (8.686e 25, 2.5559e7),
Neptune (1.024e 26, 2.4746e7),
PLUTO (1.27e 22, 1.137e6);
Private final double mass; // in kilograms
Private Final Double Radius; // in Meters
Planet (Double Mass, Double Radius) {
THIS.MASS = MASS;
THIS.RADIUS = RADIUS;
}
PRIVATE DOUBLE () {Return Mass;}
Private Double Radius () {Return Radius;}
// universal gravitational constant (M3 KG-1 S-2)
Public Static Final Double G = 6.67300E-11;
Double SurfaceGravity () {
Return G * Mass / (Radius * Radius);
}
Double SurfaceWeight (Double Othermass) {
Return Othermass * SurfaceGravity ();
}
Public static void main (String [] args) {
Double EarthWeight = Double.Parsedouble (args [0]);
Double mass = EarthWeight / Earth.surfaceGravity ();
For (Planet P: Planet.VALUES ())
System.out.printf ("Your Weight ON% S IS% F% N",
P, p.surfaceweight (mass));
}
}
