Question

我正在尝试创建一个数字猜测程序，用户输入一个数字，程序会告诉您输入是否太高，太低或正确。程序选择0-100之间的随机数。问题是当我开始测试程序时，当我选择1时，程序告诉我猜测太高了。但这是错误的，因为程序只能做整数。并且如果用户输入的数字不等于随机数，则1必须太低。有人可以看看我的代码，看看是否有什么看起来很奇怪。

int guess;
    int guess2;
    int guess3;
    int guess4;
    int guess5;
    int random = (int)Math.random() * 100;
    Scanner input = new Scanner(System.in);

    System.out.println("Try to guess a number between 0-100. You have five chances.");
    guess = input.nextInt();
    if(guess >= 100 || guess <= 0){
        System.out.println("Error, that is not a number between 0-100.");
    } else if(guess > random){
        System.out.println("The guess is too high.");
    } else if(guess < random){
        System.out.println("The guess is too low.");
    } else if(guess == random){
        System.out.println("YOU WIN");
    } else{
    }

    System.out.println("Second guess.");
    guess2 = input.nextInt();
    if(guess2 >= 100 || guess2 <= 0){
        System.out.println("Error, that is not a number between 0-100.");
    } else if(guess2 > random){
        System.out.println("The guess is too high.");
    } else if(guess2 < random){
        System.out.println("The guess is too low.");
    } else if(guess2 == random){
        System.out.println("YOU WIN");
    } else{
    }

    System.out.println("Third guess.");
    guess3 = input.nextInt();
    if(guess3 >= 100 || guess3 <= 0){
        System.out.println("Error, that is not a number between 0-100.");
    } else if(guess3 > random){
        System.out.println("The guess is too high.");
    } else if(guess3 < random){
        System.out.println("The guess is too low.");
    } else if(guess3 == random){
        System.out.println("YOU WIN");
    } else{
    }

    System.out.println("Fourth guess.");
    guess4 = input.nextInt();
    if(guess4 >= 100 || guess4 <= 0){
        System.out.println("Error, that is not a number between 0-100.");
    } else if(guess4 > random){
        System.out.println("The guess is too high.");
    } else if(guess4 < random){
        System.out.println("The guess is too low.");
    } else if(guess4 == random){
        System.out.println("YOU WIN");
    } else{
    }

    System.out.println("Last guess.");
    guess5 = input.nextInt();
    if(guess5 >= 100 || guess5 <= 0){
        System.out.println("Error, that is not a number between 0-100.");
    } else if(guess5 > random){
        System.out.println("The guess is too high.");
    } else if(guess5 < random){
        System.out.println("The guess is too low.");
    } else if(guess5 == random){
        System.out.println("YOU WIN");
    } else{
    }

Answer 1

看起来不错，但你需要改变这一行的演员阵容：

int random = (int)Math.random() * 100;

为：

int random = (int)(Math.random() * 100);

目前您的随机数始终为0.为什么？因为您将Math.random（）转换为int，而在Java中则意味着小数点后的所有内容都将丢失。（因此，0.85将变为0. 0 * 100 = 0.）通过添加括号，我们在Math.random（）乘以100之后进行投射。

另请注意，您的随机数可能为0但永远不会为100. Math.random（）返回一个大于或等于0且小于1的数字。当您将其转换为int时，99.9999将变为99

如果您希望它真的是0-100，那么你会想要这个：

int random = (int)(Math.random() * 101);

此外，您可能希望游戏在玩家获胜后终止。所以改变这个：

System.out.println("YOU WIN");

到此：

System.out.println("YOU WIN");
return;  //end

最后，永远不会调用您的空else子句。您的条件超出范围，大于随机，小于随机，等于随机。您可以安全地删除该死代码。

Answer 2

您的代码有两个主要问题：

首先：

您未能立即投射随机变量，因此随机值的值始终为0.

正确的风格是：

int random = (int)(Math.random() * 100);

<强>第二：

你的if结构很糟糕：

例如：

if(guess >= 100 || guess <= 0){

你说猜测大于等于100

你说猜测小于等于0

你用过||操作数而不是&&来检查数字是否在0和100
的范围内

试试这个：

if (guess <= 100 && guess >= 0) {
        if (guess > random) {
            System.out.println("The guess is too high.");
        } else if (guess < random) {
            System.out.println("The guess is too low.");
        } else if (guess == random) {
            System.out.println("YOU WIN");
        }
     } else {
        System.out.println("Error, that is not a number between 0-100.");
    }

说明：如果gussing number介于100和0之间，请执行以下操作。如果没有告诉用户他或她不在范围内。

Answer 3

将int random = (int)Math.random() * 100;更改为int random = (int)(Math.random() * 100);

Answer 4

你可以像这样做你的代码。很容易你可以使用for循环

    int guess;
    int random = (int) (Math.random() * 100);
    Scanner input = new Scanner(System.in);

    System.out.println("Try to guess a number between 0-100. You have five chances.");
    for (int i = 0; i < 5; i++) {
        System.out.println("Chance " + (i + 1));
        guess = input.nextInt();
        if (guess >= 100 || guess <= 0) {
            System.out.println("Error, that is not a number between 0-100.");
        } else if (guess > random) {
            System.out.println("The guess is too high.");
        } else if (guess < random) {
            System.out.println("The guess is too low.");
        } else if (guess == random) {
            System.out.println("YOU WIN");
            break;
        }
    }
    System.out.println(random);

数字猜测程序错误？

4 个答案: