Question

好的，我试图想一下如何测试从Java中的方法返回的字符串。我知道我无法测试一个字符串，但我对如何更改返回以使其能够将其作为char或其他不同的东西进行测试感到困惑。

这就是问题，我似乎无法过去。

if(flip().equals("Heads")) {
            headsCount++;
            }

完整代码

public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("How many times should I flip the coin? ");
        int headsCount = 0;
        int flips = input.nextInt();
        for(flips = flips; flips >= 1; flips--) {
            flip();
            }

        if(flip().equals("Heads")) {
            headsCount++;
            }

        System.out.println(headsCount);

    }

    public static int flip() {`enter code here`
        int rand = (int) (Math.random() * 2);
        if (rand == 1) {
            System.out.println("Heads");
            }
        if (rand != 1){
            System.out.println("tails");
            }
        return rand;
    }

Answer 1

将flip方法更改为：

    public static String flip() {
        int rand = (int) (Math.random() * 2);
        String result = null;
        if (rand == 1) {
            System.out.println("Heads");
            result = "Heads";
        }
        if (rand != 1){
            System.out.println("tails");
            result = "tails";
        }
        return result;
    }

然后，将for循环更改为以下内容：

for(flips = flips; flips >= 1; flips--) {
    String result = flip();
    if("Heads".equals(result)) {
            headsCount++;
      }
}

Answer 2

public static void main(String[] args) {
    System.out.println("How many times should I flip the coin? ");
    Scanner input = new Scanner(System.in);
    int headsCount = 0;
    int flips = input.nextInt();
    for(int flips = flips; flips >= 1; flips--) {
        flip();
        }

    if(flip() == true) {
        headsCount++;
        }

    System.out.println(headsCount);

}

public static boolean flip() {
    int rand = (int) (Math.random() * 2);
    if (rand == 1) {
        System.out.println("Heads");
        return true;
        }
    if (rand != 1){
        System.out.println("tails");
        return false;
        }
}

所以你甚至不需要比较字符串

Answer 3

当你返回一个int

应该是这样的：

//variable ensures that we are not testing a separate flip all the time
int result = flip();
if (result == 1) {
    headscount++;
} else {
    tailscount++;
}

你检索随机的方法很糟糕......很有可能是它的尾巴

Random random = new Random();
//from + random.nextInt(to - from + 1)
//0 + random.nextInt(1-0+1)
int result = random.nextInt(2);

你的for循环正在运行一个进程，然后在你的for循环之外，你正在测试单个翻转是否是头部，这与头部/尾部结果的概率和翻转的其余部分完全无关。

for(int x = 0; x < flips; x++) {
//variable ensures that we are not testing a separate flip all the time
   int result = flip();
   if (result == 1) {
          headscount++;
   } else {
          tailscount++;
   }
}

如何测试Java方法中返回的字符串

3 个答案: