Question

我必须检查用户的输入是否为int且在1-100的范围内。我知道我必须使用input.hasNextInt（）函数，但我似乎无法正确地将它放在代码中。我是编程新手，如果有人能给我任何其他的建议或建议，我将不胜感激。

import java.util.Scanner;
public class PartA {
    public static void main (String[] args){
        int numberToGuess = (int)(Math.random() * 100) + 1;
        int numberOfTries = 0;
        Scanner input = new Scanner(System.in);
        System.out.print("I'm thinking of a number. Guess a value (1-100): ");
        int guessNumber = input.nextInt();

        boolean win = false;
        while (win == false){

             numberOfTries++;


             if (guessNumber < numberToGuess) 
             {
                 System.out.print("Too Low.  Guess again: ");
                 guessNumber = input.nextInt();
             }
             else if (guessNumber > numberToGuess) 
             {
                 System.out.print("Too High.  Guess again: ");
                 guessNumber = input.nextInt();
             } 
             else
             {
                 System.out.println("Correct!  You got it in " + numberOfTries + " tries.");
                 win = true;
             }
        }
    }

Answer 1

以下更改有助于正确的操作：

public static void main(String[] args) {

    Scanner input = null;
    try {
        int numberToGuess = (int) (Math.random() * 100) + 1;
        int numberOfTries = 0;
        System.out
                .print("I'm thinking of a number. Guess a value (1-100): ");
        input = new Scanner(System.in);
        boolean win = false;
        do {
            while (!input.hasNextInt()) {    //Handle non-integer entry
                input.next();
                System.out.println("Expecting a number. Try again.");
            }
            int guessNumber = input.nextInt();
            numberOfTries++;
            if (guessNumber < numberToGuess) {
                System.out.print("Too Low.  Guess again: ");
                // guessNumber = input.nextInt(); - Reading in a single
                // place
            } else if (guessNumber > numberToGuess) {
                System.out.print("Too High.  Guess again: ");
                // guessNumber = input.nextInt(); - Reading in a single
                // place, above
            } else {
                System.out.println("Correct!  You got it in "
                        + numberOfTries + " tries.");
                win = true;
            }
        } while (!win);
    } finally {
        input.close(); // Closing the scanner stream
    }
}

如何在一个简单的猜数游戏中检查用户输入？

1 个答案: