Question

我有一个基本的问候语程序，应该根据用户的输入提出响应。我试图用for循环来完成它;但是，每当用户回复＆＃34;坏＆＃34;或者＆＃34;你＆＃34;存储在不同数组中的值，控制台多次打印出相同的响应。怎么会遇到这个问题？我在这里是一个菜鸟，在java中。如果以前已经回答过这个答案我很抱歉。我搜索但无法找到。谢谢你的时间。

import java.util.Scanner;

public class Greeter {
    public static void main(String[] args) {
        String[] greetings = { "well", "good", "great", "awesome", "fabulous" };
        String[] bad_greetings = { "bad", "awful" };
        String[] responses = { "you", "yourself" };

        System.out.println("Hello there, how are you?");
        String response;
        Scanner scan = new Scanner(System.in);
        response = scan.nextLine();
        for (String greeting : greetings) {
            if (response.contains(greeting)) {
                System.out.println("Well, good for you!");
            }
            for (String b_greet : bad_greetings) {
                if (response.contains(b_greet)) {
                    System.out.println("At least you have me.");
                }
            }
            for (String reply : responses) {
                if (response.contains(reply)) {
                    System.out.println("I'm well, thank you.");
                    // } else {
                    // System.out.println("Let's move on then.");
                    // }

                }
            }
        }

    }
}

Answer 1

改变主要（）。你的问题是你有第一个循环的错误}我建议你打破循环（或者代替break使用函数中的return;）因为如果你已经找到你的话就不需要运行所有循环答案。

public static void main(String[] args) {
    String[] greetings = {"well", "good", "great", "awesome", "fabulous"};
    String[] bad_greetings = {"bad", "awful"};
    String[] responses = {"you", "yourself"};

    System.out.println("Hello there, how are you?");
    String response;
    Scanner scan = new Scanner(System.in);
    response = scan.nextLine();
    for (String greeting : greetings) {
        if (response.contains(greeting)) {
            System.out.println("Well, good for you!");
            break;//return;
        }
    }
    for (String b_greet : bad_greetings) {
        if (response.contains(b_greet)) {
            System.out.println("At least you have me.");
            break;//return;
        }
    }
    for (String reply : responses) {
        if (response.contains(reply)) {
            System.out.println("I'm well, thank you.");
            break;//return;
            // } else {
            // System.out.println("Let's move on then.");
            // }

        }
    }
}

Answer 2

挤奶女工的回答是正确的。要进一步详细说明他的回答是你要打印你的回复5次（你的“问候”数组中每个项目一个）。

我可以想出三个解决问题的方法：

保留现有的东西，但要休息一下;声明停止for循环。
按照Milkmaid的做法拆分你的for循环并包括休息。
将数组更改为列表，而不是具有内置“包含”方法的列表。 How can I test if an array contains a certain value?

选项3将是最干净的:)你可以动态转换它或者只是从一个列表开始。好像你的程序可以从列表开始。

Answer 3

您可以尝试以下

public static void main(String[] args) {
String[] greetings = {"well", "good", "great", "awesome", "fabulous"};
String[] bad_greetings = {"bad", "awful"};
String[] responses = {"you", "yourself"};

System.out.println("Hello there, how are you?");
String response;
Scanner scan = new Scanner(System.in);
response = scan.nextLine();
if(Arrays.asList(greetings).contains(response)){
      System.out.println("Well, good for you!");
      break;//return;
}
if(Arrays.asList(bad_greetings).contains(response)){
      System.out.println("At least you have me.");
      break;//return;
}
if(Arrays.asList(responses).contains(response)){
      System.out.println("I'm well, thank you.");
      break;//return;
}
 // } else {
 // System.out.println("Let's move on then.");
 // }

}

嵌套for循环打印太多值java

3 个答案: