Question

我目前正在完成我的第一个基于随机数游戏的java课程和作业。如果有更多和更少的陈述，我会遇到一些问题。

我非常感谢一些一般性意见。

我希望输入“随机”号码的原因是出于测试目的我还需要合并get()和set()方法，因为赋值需要面向对象的编程，所以我需要使用多个类

任何建议都将受到高度赞赏

我遇到的问题是检查随机数的最后一个if语句在范围内总是得到输出超出范围

 package randomnumbergame;

 /*
  * @author Matthew O
  */

import java.util.Scanner;
public class Main {


public static void main(String[] args)
{


int numGuesses = 3;
int rangeMin = 1;
int rangeMax = 10;
int randomNum = 0;

Scanner scan = new Scanner (System.in);


System.out.println("Welcome to the random number game!");
System.out.println("The object of this game is to correctly "
+"guess a number between a set range within a certain ammount of guesses.");
System.out.println("\nThe default range is " + rangeMin + " - " + rangeMax); 
System.out.println("Would you like to change this?");                          
System.out.println("Please enter y for yes or n for no and press enter.");

String range = scan.nextLine();           
char changeRange = range.charAt(0);    
if (! (changeRange == 'Y' || changeRange == 'y'|| changeRange == 'n' || changeRange == 'N'))  
    {
    System.out.println("Error: invalid input entered for the interstate question");   
    System.exit(0);                                                          
    }                                                                           

if (changeRange == 'Y' || changeRange == 'y')       
    {
    System.out.println ("\nPlease enter the new numerical minimum value for the range");      
    int newRangeMin = scan.nextInt();                                              
    rangeMin = newRangeMin;                                  
    System.out.println ("\nPlease enter the new maximum numerical value for the range");       
    int newRangeMax = scan.nextInt();                                               
    rangeMax = newRangeMax;         
    }

{
System.out.println("\nThe default number of guesses is " + numGuesses);         
System.out.println("Would you like to change this?");                           
System.out.println("\nPlease enter y for yes or n for no and press enter.");    

String guesses = scan.next();                                                  
char changeGuesses = guesses.charAt(0);                                         
if (! (changeGuesses == 'Y' || changeGuesses == 'y' || changeGuesses == 'n' || changeGuesses 
== 'N'))                           

    {
System.out.println("Error: invalid input entered for the interstate question");           
System.exit(0);
    }

if (changeGuesses == 'Y' || changeGuesses == 'y')
    {
System.out.println("\nPlease enter the new number of permitted guesses");       
int newGuesses = scan.nextInt();                                               
numGuesses = newGuesses;                                                       
    }

    {
System.out.println ("\n\n\n\n\n\n\n\n\n");                                     
System.out.println("Welcome to the random number game!\n");                     
System.out.println("You have chosen a range of " + rangeMin + " to " + rangeMax);
System.out.println("You have chosen to have " + numGuesses + " Guesses");       
    }
}

{
System.out.println("\nPlease press y to input the random number or n" + 
" to let the number be automatically generated");           
String random = scan.next();                                                    
char changeRandom = random.charAt(0);                                          
if (! (changeRandom == 'Y' || changeRandom == 'y' || changeRandom == 'n' || 
changeRandom == 'N'))                            
    {
    System.out.println("Error: invalid input entered for the interstate question");     
    System.exit(0);
    }

   if (changeRandom == 'Y' || changeRandom == 'y')  
    {
    System.out.println("\nPlease enter the new 'random' number between "
    + rangeMin + " and " + rangeMax);                           
    int inputRandom = scan.nextInt();                                     
    randomNum = inputRandom;                                             
    System.out.println("\nThe 'random' number chosen for the game is " + randomNum);          
    }

if (randomNum < rangeMin);    
    {
    System.out.println("Random number is out of range!");     
    }

    }


 }

}

Answer 1

您在;语句的末尾有一个不必要的if，所以即使进行了评估，结果也一无所获。

if (randomNum < rangeMin); 
            {
                System.out.println("Random number is out of range!");           
            }

无论如何评估if，都会始终打印消息。

将上述内容更改为：

 if (randomNum < rangeMin)
                {
                    System.out.println("Random number is out of range!");           
                }

Answer 2

if (randomNum < rangeMin);
{
    System.out.println("Random number is out of range!");
}

问题在于第一行的;（分号）。 Java认为它是if条件的结束，并且每次都会打印出错误消息。声明然后说：

“if（randomNum＆lt; rangeMin），什么都不做。然后打印出'随机数超出范围！'。”

Answer 3

在if之后删除;符号。

if (randomNum < rangeMin);
{
System.out.println("Random number is out of range!");
}

随机数游戏帮助 - if语句问题

3 个答案: