java - 变量声明错误 - 重复的局部变量

Question

各位，我是java新手，大约几周前才开始接触。我正在尝试制作一个猜谜游戏程序，您必须猜测 1 到 100 之间的数字，但有一个问题。

代码:

import java.util.Scanner;
import java.util.Random;

public class CODE {

    public static void main(String[] args) {
        Random rand = new Random();
        int n = rand.nextInt(100) + 1;
        Scanner input = new Scanner(System.in);

        System.out.println(n);
        System.out.println("Lets play a guessing game! You try to guess the number I am thinking \n");
        System.out.println("Guess a number between 1 to 100! ");

        String inputLine = input.nextLine();
        int line = Integer.parseInt(inputLine);

        boolean gotIt;
        gotIt = false;
        while(gotIt == false) {
            if (n < line) {
                System.out.println("Go Lower");
                String inputLine = input.nextLine();
                line = Integer.parseInt(inputLine);
            }
            if (n > line) {
                System.out.println("Go Higher");
                String inputLine = input.nextLine();
                line = Integer.parseInt(inputLine);
            }
            if (line == n) {
                System.out.println("You guessed my number!!!");
                gotIt = true;
                break;
            }
        }   
    }
}

但是它给了我一个错误:

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
    Duplicate local variable inputLine
    Duplicate local variable inputLine

    at CODE.main(CODE.java:23)

有什么帮助吗？

Answer 1

这个错误是非常不言自明的，这意味着你声明了一个变量 inputLine 两次。

一旦用StringvariableName声明了一个变量，你就不能再这样做了，你只需要用variableName引用创建的变量，这样你就可以覆盖中的引用内存到新值。

喜欢:

public class CODE {

public static void main(String[] args) {
    Random rand = new Random();
    int n = rand.nextInt(100) + 1;
    Scanner input = new Scanner(System.in);

    System.out.println(n);
    System.out.println("Lets play a guessing game! You try to guess the number I am thinking \n");
    System.out.println("Guess a number between 1 to 100! ");

    String inputLine = input.nextLine();
    int line = Integer.parseInt(inputLine);

    boolean gotIt;
    gotIt=false;
    while(gotIt==false) {
        if (n<line) {
            System.out.println("Go Lower");
            inputLine = input.nextLine();
            line = Integer.parseInt(inputLine);
        }
        if (n>line) {
            System.out.println("Go Higher");
            inputLine = input.nextLine();
            line = Integer.parseInt(inputLine);
        }
        if (line==n) {
            System.out.println("You guessed my number!!!");
            gotIt=true;
            break;
        }
    }

}