如果输入不是整数，java会反复请求用户输入

Question

正如标题所说，如果给定的输入无效，我试图让我的程序重新请求用户输入（在本例中，无效输入是指任何不是整数的输入）

我已经试过了，但不管用：

import java.util.Scanner;

public class Main {



    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        System.out.println("Please input your age");

        if (scanner.hasNextInt()) {
            int age = scanner.nextInt();
            System.out.println("Your age is: " + age);
            System.out.println();
        } else {
            System.out.println("This input is not an integer - Please try again!");
            int age = scanner.nextInt();
            System.out.println("Your age is: " + age);
            System.out.println();

        }
    }
}

我的目标是通过while loop和scanner

我当前的代码：

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {



        Scanner scanner = new Scanner(System.in);
        System.out.println("Please input your age");


        if (scanner.hasNextInt()) {
            int age = scanner.nextInt();
            System.out.println("Your age is: " + age);

        }
    }
}

非常感谢您对本帖的回复

Answer 1

我认为你应该用while代替if语句。输入正确后中断。试试看

Answer 2

你可以使用while-loop：

Scanner scanner = new Scanner(System.in);
boolean ageGiven = false;

while (!ageGiven) {
    System.out.println("Please input your age");
    String next = scanner.next();
    try {
        int age = Integer.parseInt(next);
        System.out.println("Your age is: " + age);
        ageGiven = true;
    } catch (NumberFormatException e) {
        System.out.println("This input is not an integer - Please try again!");
    }
}