为什么我必须先输入两个整数才能进行迭代？ hasInt(), nextLine(), nextInt()

Question

当我尝试运行时，我必须输入 2 个整数并进入循环才能移动到下一次迭代，但第二次循环不会发生这种情况？这是什么原因，解决这个问题的逻辑是什么？

import java.util.Scanner;

public class MinAndMaxInputChallenge {
    public static void main(String[] args) {
        int max = 0;
        int min = 0;
        int number;
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.println("Enter number ");
            number = scanner.nextInt();
            boolean hasInt = scanner.hasNextInt();
            scanner.nextLine();
            if (hasInt) {
                if (number > max)
                    max = number;
                else if (number < min)
                    min = number;
            } else break;
        }
        System.out.println("Max = " + max + " Min = " + min);
        scanner.close();
    }
}

Code & Ouput

Answer 1

你的代码逻辑有点不对劲。首先检查 kb 的缓冲区中是否有 int。如果是，读入，消耗 eol，设置 min 或 max，然后跳出 while 循环

import java.util.Scanner;

public class MinAndMaxInputChallenge {
    public static void main(String[] args) {
        int max = 0;
        int min = 0;
        int number;
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.println("Enter number ");
            
            boolean hasInt = scanner.hasNextInt();
            
            if (hasInt) {
                number = scanner.nextInt();
                scanner.nextLine();
                if (number > max)
                    max = number;
                else if (number < min)
                    min = number;
                break;
            } 
        }
        System.out.println("Max = " + max + " Min = " + min);
        scanner.close();
    }
}

为什么我必须先输入两个整数才能进行迭代？ hasInt(), nextLine(), nextInt()

Why do I have to enter two integer at first to proceed to the iteration? hasInt(), nextLine(), nextInt()

java

java.util.scanner