航站楼"Incomparable types: java.lang.String and int"

Question

我在学校编写一个简单的Java程序来猜测正确答案，当我把它带回家时，它遇到了错误。

起初我将 TerminalIO.KeyboardReader 更改为 java.util.Scanner，现在当我通过 Terminal 运行它时，它返回"无与伦比的类型：java.lang.String 和 int"。

有什么帮助吗？真的很困惑。

法典：

import java.util.Scanner;
import java.util.Random;
public class guess { 
       public static void main(String [] args) {
           Scanner keyboard = new Scanner(System.in);
           Random generator = new Random();
           System.out.println("I am thinking of a number from 1 to 10.");
           System.out.println("You must guess what it is.");
           System.out.print("Enter a guess: ");
           int randomNumber = generator.nextInt(10) + 1;
           String x = keyboard.nextLine();
           int guessNum = 1;
           while (x != randomNumber) {
                  System.out.println("Guess again!");
                  x = keyboard.nextLine();
                  guessNum ++;
                }
                System.out.println("RIGHT!");
                System.out.println("You got it correct in " +guessNum + " guesses.");
}

}

Answer 1

您无法比较 int 和 String。

您可以这样做：

int someInt = 6;
String someString = "6";
String intAsString = Integer.toString(someInt);
if (someString.equals(intAsString)) {
    System.out.println("Yay");
}

---

您可以将字符串转换为如下所示的数字：

int someInt = 6;
String someString = "6";
try {
    int stringAsInt = Integer.parseInt(someString);
    if (stringAsInt == someInt) {
        System.out.println("Yay");
    }
}
catch (NumberFormatException nfe) {
    System.out.println("String is not an integer");
}

Answer 2

您正在比较字符串和 int（这是不兼容的类型）

将您的 int 转换为字符串并进行比较

       while (!(x.equals(Integer.toString(randomNumber)))) {