Question

我有一个小代码：

    Scanner vloz = new Scanner(System.in);
    int cisla = 0;
    int i = 0;
    while(i < 10){
            try {
                System.out.println("Vloz cislo " + i + ":");
                int cislo = Integer.parseInt(vloz.nextLine());
                 ++i;
                cisla = cisla + cislo;
                }
            catch(InputMismatchException exception){
                System.out.println("Nevlozil si cislo!");
                }
            }
    float priemer = cisla / i;
    System.out.println("Priemer cisel je " + priemer + ".");
    }   
}

但总是当我运行它并键入其他charakters然后int，程序崩溃并没有运行“catch”。该程序的目标是当另一个int输入显示错误消息时，不要添加到int i并为用户添加另一个选项来添加整数。

Answer 1

您需要抓住NumberFormatException而不是InputMismatchException，如此：

import java.util.Scanner;

class Main {
  public static void main(String[] args) {
    Scanner vloz = new Scanner(System.in);
    int cisla = 0;
    int i = 0;
    while(i < 10){
      try {
        System.out.print("Vloz cislo " + i + ":");
        int cislo = Integer.parseInt(vloz.nextLine());
        i++;
        cisla = cisla + cislo;
      } catch(NumberFormatException exception) {
        System.out.println("Nevlozil si cislo!");
      }
    }
    float priemer = cisla / i;
    System.out.println("Priemer cisel je " + priemer + ".");
  }   
}

试试here!

Answer 2

你抓住了错误的例外。方法parseInt(String s)会引发NumberFormatException 而非 a InputMismatchException。将您的catch子句更改为catch(NumberFormatException exception)。

Answer 3

import java.util。*; 公共课演示{

public static void main (String []args ){

    Scanner vloz = new Scanner(System.in);
    int cisla = 0;
    int i = 0;
    while(i < 10){
            try {
                System.out.println("Vloz cislo " + i + ":");
                int cislo = Integer.parseInt(vloz.nextLine());
                 ++i;
                cisla = cisla + cislo;
                }
            catch(InputMismatchException exception){
                System.out.println("Nevlozil si cislo!");
                }
            }
    float priemer = cisla / i;
    System.out.println("Priemer cisel je " + priemer + ".");

}

}

我不确定它崩溃的原因但这段代码有效。我想你可能忘了import.java。*;

输入不匹配int

3 个答案: