"Enter another number (Y/N?)"流程重新开始，而不是在"Y"时继续

Question

我有两个程序：

Score.java设置为执行以下操作：

• 从键盘上读取分数并打印其平均值
• 分数将是数字，可能包括小数部分

例如，分数可能是8.73或诸如此类。不同的比赛将有不同数量的评委。它将不断询问和阅读分数，直到用户键入"完成"。然后程序将打印总分、分数和平均分数。然后，该程序将提示用户查看是否还有其他参赛者。如果有，则再次开始提示得分。如果没有，则退出程序。"我将其设置为当您输入"N"时停止程序，并设置为在输入"Y"后将未来的条目添加到计算中。

import java.util.Scanner;
// This is the Score program
// Written by me
public class Score
{
public static void main(String args[])
{
Scanner game = new Scanner(System.in);
double num = 0.0;
double sum = 0.0;
int cnt = 0;
while (true)
{
System.out.println("Enter as many non-negative integers as you like ");
System.out.println("one at a time and I will find the average");
System.out.println("Enter done to stop entering numbers");
System.out.print("enter number: ");
String ans = game.next();
while (!ans.equals("done"))
{
num = Double.parseDouble(ans);
sum = sum + num;
cnt = cnt + 1;
System.out.print("enter number: ");
ans = game.next();
}
System.out.println(cnt);
System.out.println(sum);
System.out.println("Total Score " + sum + " count scores " + cnt + " avg score " + sum / cnt);
System.out.println("Enter another contestant (Y/N)?");
String str = game.next();
if (!str.equals("Y"))
break;
}
}
}

虽然上述过程有效，但在键入"Y"添加更多分数后，我无法使我的第二个程序Olympic.java正常工作。相反，它开始了一个全新的平均值计算，而不是添加到以前的计算中：

import java.util.Scanner;
// This is the Olympic program
// Written by me
public class Olympic
{
public static void main(String args[])
{
Scanner game = new Scanner(System.in);
double num = 0.0;
double sum = 0.0;
int cnt = 0;
double highscore = Double.MAX_VALUE;
double lowscore = Double.MIN_VALUE;
while (true)
{
System.out.println("Enter as many non-negative integers as you like ");
System.out.println("one at a time and I will find the average");
System.out.println("Enter done to stop entering numbers");
System.out.print("enter number: ");
String ans = game.next();
lowscore = game.nextDouble();
highscore = game.nextDouble();
while (!ans.equals("done"))
{
num = Double.parseDouble(ans);
sum = (sum + num) - lowscore - highscore;
cnt = cnt + 1;
System.out.print("enter number: ");
if (num > highscore)
{
highscore = num;
}
if (num < lowscore)
{
lowscore = num;
}
ans = game.next();
}
System.out.println("Throwing out low score " + lowscore + " and high score " + highscore);
System.out.println("Total Score " + sum + " count scores " + cnt + " avg score " + sum / cnt);
System.out.println("Enter another contestant (Y/N)?");
String str = game.next();
if (!str.equals("Y"))
break;
}
}
}

Answer 1

所以我做了一个非常快速的测试

public static void main(String[] args) {
Scanner game = new Scanner(System.in);
while (true) {
System.out.println("Enter another contestant (Y/N)?");
String str = game.next();
if (!str.equalsIgnoreCase("Y")) {
break;
}
}
System.out.println("I'm free");
}

这将很好地退出。

至于你的第二个问题。我认为你的逻辑有点扭曲。你可以试试。。。

Scanner game = new Scanner(System.in);
double num = 0;
double sum = 0;
int cnt = 0;
while (true) {
System.out.println("Enter as many non-negative integers as you like ");
System.out.println("one at a time and I will find the average");
System.out.println("Enter done to stop entering numbers");
double lowscore = Double.MAX_VALUE;
double highscore = 0;
System.out.print("enter number: ");
String ans = game.next();
while (!ans.equals("done")) {
num = Double.parseDouble(ans);
lowscore = Math.min(lowscore, num);
highscore = Math.max(highscore, num);
sum += num;
cnt++;
System.out.print("enter number: ");
if (num > highscore) {
highscore = num;
}
if (num < lowscore) {
lowscore = num;
}
ans = game.next();
}
sum -= lowscore;
sum -= highscore;
System.out.println("Throwing out low score " + lowscore + " and high score " + highscore);
System.out.println("Total Score " + sum + " count scores " + cnt + " avg score " + sum / cnt);
System.out.println("Enter another contestant (Y/N)?");
String str = game.next();
if (!str.equalsIgnoreCase("Y")) {
break;
}
}

这将输出。。。

Enter as many non-negative integers as you like 
one at a time and I will find the average
Enter done to stop entering numbers
enter number: 1
enter number: 2
enter number: 3
enter number: 4
enter number: 5
enter number: 6
enter number: 7
enter number: 8
enter number: 9
enter number: 10
enter number: done
Throwing out low score 1.0 and high score 10.0
Total Score 44.0 count scores 10 avg score 4.4
Enter another contestant (Y/N)?
y
Enter as many non-negative integers as you like 
one at a time and I will find the average
Enter done to stop entering numbers
enter number: 1
enter number: 12
enter number: 13
enter number: 14
enter number: 15
enter number: 16
enter number: 17
enter number: 18
enter number: 19
enter number: 20
enter number: done
Throwing out low score 1.0 and high score 20.0
Total Score 168.0 count scores 20 avg score 8.4
Enter another contestant (Y/N)?
n

至于你的例外。当使用Scanner.nextDouble时，如果输入不能作为double进行解析，它将抛出异常。你需要在你认为合适的时候处理这种情况。。。