如何继续要求用户输入正确的数字

Question

我需要使用一个 while 循环来询问用户一个介于 1-100 之间的数字，如果他们输入任何负数或超过 100 的数字，则告诉用户他们输入了错误的数字。这就是我到目前为止。每当我运行它时，它都会要求用户输入。当输入为负数或大于 100 时，表示无效数字，而当用户输入为 45 时，仍然表示无效数字，当 0-100 之间的数字有效时。我不认为它在阅读代码的最后一部分。

import java.util.*;

public class PlayOffs {
    public static Scanner scan = new Scanner(System.in);

    public static void main(String[] args) {

        System.out.print("What is the % chance Team 1 will win (1-99)?: ");
        int team1input = scan.nextInt();
        do {
            while (team1input >= -1 || team1input >= 101) {
                System.out.println("That's not between 1-99");
                scan.next(); // this is important!
            }
            team1input = scan.nextInt();
        } while (team1input >= 0 && team1input <= 100);
        System.out.println("Thank you! Got " + team1input);
    }
}

Answer 1

您的比较有问题。
您不需要两个循环。
这段代码可能合适。

import java.util.Random;
import java.util.*;

    public class PlayOffs {
        public static Scanner scan = new Scanner(System.in);

        public static void main(String[] args) {

            System.out.print("What is the % chance Team 1 will win (1-99)?: ");
            int team1input = scan.nextInt();
            do {
                if(!(team1input >= 0 && team1input <= 100)) {
                    System.out.println("That's not between 1-99");
                    scan.next(); // this is important!
                    team1input = scan.nextInt();
                }

            } while (!(team1input > -1 && team1input  <101));
            System.out.println("Thank you! Got " + team1input);
        }
    }

Answer 2

您的问题在于您的 while 循环：

while (team1input >= -1 || team1input >= 101)

45 >= -1？ => true，这就是它打印无效的原因。

实际上，您不需要 2 个循环。 do-while 循环足以获得您想要的结果：

import java.util.*;

public class PlayOffs {
    public static Scanner scan = new Scanner(System.in);

    public static void main(String[] args) {

        System.out.print("What is the % chance Team 1 will win (0-100)?: ");
        boolean validNumber;
        int team1input;
        do {
            team1input = scan.nextInt();
            validNumber = team1input >= 0 && team1input <= 100;

            if (!validNumber) {
                System.out.println("That's not between 0-100");
            }

        } while (!validNumber);
        System.out.println("Thank you! Got " + team1input);
    }
}

运行输出：

第 1 队获胜的几率是多少（0-100）？：-1
那不是 0-100之间
105
那不是0-100之间
101
那是 不在 0-100 之间
45
谢谢！得到 45