java 制作彩票申请：用随机数填充数组
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Making a lottery application: fill array with random numbers
提问by Steven Eck
I am making a lottery application in Java. My problem is that I think everything is in place and it (the IDE) is telling me that "int lotteryNumbersCount = Eck_LotteryClass.getLotteryNumbers().length;" needs to be static. So I change it to a static int and then I have to change it again in my class. Problem is when I finally run it I get all 0's for my random lottery data. Please help me find the errors in my ways. Total newb here and I've been looking online here but I want to try to figure it out without just copying code somewhere.
我正在用 Java 制作一个彩票应用程序。我的问题是我认为一切都已就位，它（IDE）告诉我“ int lotteryNumbersCount = Eck_LotteryClass.getLotteryNumbers().length;”需要是静态的。所以我将它更改为静态 int，然后我必须在我的班级中再次更改它。问题是当我最终运行它时，我的随机彩票数据全部为 0。请帮我找出我的方法中的错误。这里完全是新手，我一直在这里在线查找，但我想尝试弄清楚，而不仅仅是在某处复制代码。
Eck_LotteryClass
Eck_LotteryClass
import java.util.Random;
public class Eck_LotteryClass {
//instance field
private int lotteryNumbers [];
//Create random lottery numbers method array
public int [] getRandomNumbers(){
lotteryNumbers = new int [5];
Random r = new Random();
for(int i = 0; i < 5; i++)
lotteryNumbers[i] = r.nextInt(10);
return lotteryNumbers;
}
public int compareNumbers(int[] usersNumbers) {
int matchedNums = 0;
if (usersNumbers.length == lotteryNumbers.length) {
for (int i = 0; i < lotteryNumbers.length; i++) {
if (usersNumbers[i] == lotteryNumbers[i]) {
matchedNums ++;
}
}
}
return matchedNums;}
// Display the random lottery numbers for the user
public int [] getLotteryNumbers() {
return lotteryNumbers;
}
}
Eck_LotteryTester
Eck_LotteryTester
import java.util.Scanner;
import java.util.Arrays;
public class Eck_LotteryTester{
public static void main(String[] args) {
Eck_LotteryClass lottery = new Eck_LotteryClass();
int lotteryNumbersCount = Eck_LotteryClass.getLotteryNumbers().length;
System.out.println("The Pennsylvania Lottery\n");
System.out.println("There are " + lotteryNumbersCount
+ " numbers in my lottery, they are 0 through 9. "
+ "See if you can win big CASH prizes!!!\n");
// Asks the user to enter five numbers.
Scanner keyboard = new Scanner(System.in);
int numbers[] = new int[lotteryNumbersCount];
for (int index = 0; index < numbers.length; index++) {
System.out.print(String.format("Enter Number %d: ", index + 1));
numbers[index] = keyboard.nextInt();
}
// Display the number of digits that match the randomly generated
// lottery numbers.
int match = lottery.compareNumbers(numbers);
if (match == lotteryNumbersCount) {
// If all of the digits match, display a message proclaiming the
// user a grand prize winner.
System.out.println("\nYOU WIN, GO SEE D. LEETE FOR YOUR GRAND PRIZE!!!");
} else {
System.out.println("\nThe winning numbers are " + Arrays.toString(Eck_LotteryClass.getLotteryNumbers()) +
"\nYou matched " + match + " number(s).");
}
}
}
回答by DigCamara
Change
改变
int lotteryNumbersCount = Eck_LotteryClass.getLotteryNumbers().length;
to
到
int lotteryNumbersCount = lottery .getLotteryNumbers().length;
and you won't have to change the methods signature to static. Also you'll be talking about the same variable.
并且您不必将方法签名更改为静态。您还将谈论相同的变量。
Also change
也变
// Display the random lottery numbers for the user
public int [] getLotteryNumbers() {
return lotteryNumbers;
}
to
到
// Display the random lottery numbers for the user
public int [] getLotteryNumbers() {
return getRandomNumbers();
}
So the array gets initialized. And changing the signature of
所以数组被初始化。并更改签名
public int [] getRandomNumbers
to
到
private int [] getRandomNumbers
wouldn't hurt
不会痛
回答by Harsh Kevadia
package New_list;
import java.util.Scanner;
import java.util.Random;
public class Lottery {
private static Scanner scan;
public static void main(String[] args) {
System.out.println("\t\t\tWelcome to Harsh Lottery System.\n");
Random random = new Random();
int lottery_win_1 = random.nextInt(10);
// Print Lottery winning number...1 :P
// System.out.println(lottery_win_1 + "\n");
int lottery_win_2 = random.nextInt(10);
// Print Lottery winning number...2 :P
// System.out.println(lottery_win_2 + "\n");
boolean loop = true;
while(loop){
System.out.println("\t\t\tEnter your 2 Digit Lottery number.\n");
scan = new Scanner(System.in);
int lottery_no = scan.nextInt();
if ((lottery_no >= 0) && (lottery_no <= 99)) {
int lottery_no_1, lottery_no_2;
if (lottery_no > 9) {
lottery_no_1 = lottery_no / 10;
lottery_no_2 = lottery_no % 10;
} else {
lottery_no_1 = 0;
lottery_no_2 = lottery_no;
}
if ((lottery_win_1 == lottery_no_1)
&& (lottery_win_2 == lottery_no_2)) {
System.out
.println("\t\t\tCongratulation you win lottery,and you win 000.\n");
} else if ((lottery_win_1 == lottery_no_2)
&& (lottery_win_2 == lottery_no_1)) {
System.out
.println("\t\t\tCongratulation your inverse no is lottery winer number so that you win 00.\n");
} else if ((lottery_win_1 == lottery_no_1)
|| (lottery_win_1 == lottery_no_2)
|| (lottery_win_2 == lottery_no_1)
|| (lottery_win_2 == lottery_no_2)) {
System.out
.println("\t\t\tCongratulation your one digit from your lotter number match to the lottery winner.so you win 00.\n");
} else {
System.out.println("\t\t\tSorry,Please try again\n");
System.out.println("\t\t\tDo you want to try again\n\t\t\tPress 1 for Continue\n\t\t\tPress 2 for exit\n");
int ch = scan.nextInt();
switch(ch){
case 1: System.out.println("\t\t\tOk...Try again\n");
break;
case 2: System.out.println("\t\t\tBbye... See you later\n");
loop = false;
break;
}
}
} else {
System.out.println("\t\t\tSorry,Please choose 2 digit number\n");
}
}
}
}
