java - 无法检查用户输入是否小于某个数字

Question

当我输入小于 12 的数字时没有问题，但当我输入更大的数字时，我会得到“输入小于 13 的数字”，并且在后续输入中始终会出现该问题。我怎样才能让程序检查 int 和小于 13 的数字？

package com.company;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        Scanner z = new Scanner(System.in);
        boolean cont;
        boolean isNumber;

        do {
            System.out.println("Enter the number you want to see the factorial of (0-12)");
            do{
                if(s.hasNextInt()){
                    isNumber = true;
                }else{
                    isNumber=false;
                    System.out.println("Enter a number");
                    s.next();
                }
            }while(!isNumber);
            int input = s.nextInt();

            boolean isSmall;
            do{
                if(input < 13){
                    isSmall= true;

                }else{
                    isSmall=false;
                    System.out.println("Enter a number less than 13");
                    s.next();
                }
            }while(!isSmall);

            int factorial = 1;
            System.out.print(input + "!" + " = ");
            for ( int i =1 ; i<=input ;  i++) {
                factorial *= i;
                System.out.print(i);
                if (input == i) {
                    break;
                }

                System.out.print(" * ");
            }
            System.out.println(" = " + factorial);

            System.out.println("Do you want to continue?");
            String line = z.nextLine();
            if(line.matches("y|YES|Y|yes|Yes")){
                cont=true;
            }else{
                cont= false;
                System.out.println("Thanks for using the program!");
            }
        }while(cont);
    }
}

Answer 1

您忘记将新值放入输入中，因此您总是比较较大的值 13

do{
    if(input < 13){
         isSmall= true;
     }else{
           isSmall=false;
           System.out.println("Enter a number less than 13");
           input =  s.nextInt();
      }
  }while(!isSmall);