java为什么一个整数应该更新为不同的值时会重置为100

Question

下面的代码墙应该在循环运行时随时更改“lowestguess”和“highestguess”的值。理想情况下，它意味着将最高猜测从100降低到1，使最低猜测从1提高到1，这样程序就不能猜出比已经猜到的更低或更高的数字（减少完成程序所需的循环次数）

但是，每次运行“takestab”功能时，最低猜测和最高猜测总是重置为默认值，分别为1和100。不知道这里发生了什么，因为我没有收到任何错误

是否可能因为这里的方法是私有的，所以它们不更新各自作用域之外的变量

import java.util.Scanner;

public class AIGuessing
{
    public static void main(String[]args) 
    {
        //DECLARATIONS*
        Scanner inputReader = new Scanner(System.in);
        int number;
        int guess;
        int guesses = 0;
        int lowestguess = 1;
        int highestguess = 100;

        //code
        System.out.println("Welcome!");
        System.out.println("Please enter a number for the AI to guess");
        number = inputReader.nextInt();

        //computer tries to guess number
        do
        {
            guesses++;
            guess = takestab(lowestguess, highestguess, number);
            System.out.println("\"I guess " +guess+ ".\"");
        }while(guess != number);

        if(guess == number)
        {
            System.out.println("WOO! I got it!");
        }

        if(guesses >= 1 && guesses ==2)
        {
            System.out.println(guesses + " guesses? I..AM...GOD!!!!");
        }
        else if(guesses >= 3 && guesses <= 5)
        {
            System.out.println(guesses + " guesses? Hooray! I'm as average as gravy!!!");
        }
        else if(guesses >= 6 && guesses <= 8)
        {
            System.out.println(guesses + " guesses? I only guess when I'm drunk");
        }
        else if(guesses >= 9)
        {
            System.out.println(guesses + " guesses? Bugger me... turn me into scrap");
        }
        //end code
    }

    public static int takestab(Integer lowestguess, Integer highestguess, Integer number)
    {  

        int estimate;
        estimate = estimate(lowestguess, highestguess);
        System.out.println("Estimate is: "+estimate+".");

        if(estimate < number && estimate > lowestguess)
        {
            lowestguess = estimate;
            barkchange(lowestguess, highestguess, estimate);
        }
        else if(estimate > number && estimate < highestguess)
        {
            highestguess = estimate;
            barkchange(lowestguess, highestguess, estimate);
        }
                return estimate;
    }

    //function to generate and return a random number
    public static int estimate(int low, int high)
    {
        int comGuess;
        comGuess = (low + (int)(Math.random() * ((high - low) + low)));
        return comGuess;
    }

    //function to 'bark' the changes of lowest and highest guesses
    public static void barkchange(Integer lowestguess, Integer highestguess, Integer guess)
    {
        System.out.println("Current guess is: "+guess+".");
        System.out.println("Lowest guess is: "+lowestguess+".");
        System.out.println("Highest guess is: "+highestguess+".\n");
    }
}

Answer 1

整数是一个不可变的对象

lowestguess = estimate;

在这一行（以及highestguess）中，您正在更改lowestguess的本地副本，而不是您传递给它的副本

在这种情况下，最简单的解决方案是将lowestguess和highestguess声明为“全局”（静态）

在你的主要位置之上

static int highestGuess = 100;
static int lowestGuess = 1;

然后，您可以将参数删除到方法中，而不必再传入它们。您可以直接引用静态的

挑剔者的旁白：我在这里使用“全局”，因为这里没有OO。在此上下文中，静态变量是全局变量