有没有办法消除 (var) = Scanner.nextInt();声明？

Question

有没有办法在遵循这些规范的同时优化代码？教授无法获得直接帮助。包括规格的屏幕截图。

这是我交上来的代码，按照说明：

该程序必须使用以下方式完成 仅 4 个整数变量用于存储用户定义的种子值、每个用户定义的猜测（仅需要一个变量来存储所有用户定义的猜测）、每次随机生成的硬币翻转（仅需要一个变量）需要存储所有抛硬币的次数）以及正确猜测的总数。 仅将 1 个扫描仪对象实例分配给用于读取种子和用户猜测的引用变量， 仅 1 个随机对象实例化，该实例化使用用户定义的输入作为种子，并分配给用于为抛硬币生成 0 或 1 的引用变量，以及 几个 if/else 语句，以及 几个打印语句。 代码应该高效地编写 消除冗余编码和 消除仅使用一次的变量。

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

public class CoinToss {
  public static void main(String[] args) {
    Toss();
  }
   
   //In this method, the computer simulates flipping a coin and the user guesses
   //the result; the computer will report the status of each guess after each
   //coin toss and the tabulate the cumulative results after 5 coin tosses.
   //Note: The computer will use 0 to represent "heads" and 1 to represent 
   //      "tails" for each coin toss.
  public static void Toss()  {
   //Initiate new scanner.
   Scanner scanner = new Scanner(System.in);

   //User introduction to the program.
   System.out.println("This program will repeatedly prompt the user for a guess to a coin toss.");
   System.out.println("Note: 0 is heads and 1 is tails.\n");

   //Prompting user for seed, then storing it in an int variable. 
   System.out.println("Enter the seed for the Random object.");
   int seed = scanner.nextInt();
   Random random = new Random(seed);

   //Initializing 3 variables, they will be used later.
   int userGuess, coinFlip, correctGuesses = 0;

   /*The program will ask the user for a guess, either 1 or 2, and will store
      the guess within the userGuess variable. It will then flip a coin, then
      using an if/else statement, if the user guesses right, the number of 
      correct guesses goes up, and is stored in a variable. This process is 
      repeated 5 times. 
   */
   // Trial 1
   System.out.println("\nWhat is your guess for trial #1?");
   userGuess = scanner.nextInt();
   coinFlip = random.nextInt(2);
   System.out.println("The coin toss was a " + coinFlip + ".");

   if (userGuess == coinFlip) {
     System.out.println("You guessed right!");
     correctGuesses++;
   } else {
     System.out.println("Sorry, try again next time!");
   }

   // Trial 2
   System.out.println("\nWhat is your guess for trial #2?");
   userGuess = scanner.nextInt();
   coinFlip = random.nextInt(2);
   System.out.println("The coin toss was a " + coinFlip + ".");

   if (userGuess == coinFlip) {
     System.out.println("You guessed right!");
     correctGuesses++;
   } else {
     System.out.println("Sorry, try again next time!");
   }

   // Trial 3
   System.out.println("\nWhat is your guess for trial #3?");
   userGuess = scanner.nextInt();
   coinFlip = random.nextInt(2);
   System.out.println("The coin toss was a " + coinFlip + ".");

   if (userGuess == coinFlip) {
     System.out.println("You guessed right!");
     correctGuesses++;
   } else {
     System.out.println("Sorry, try again next time!");
   }

   // Trial 4
   System.out.println("\nWhat is your guess for trial #4?");
   userGuess = scanner.nextInt();
   coinFlip = random.nextInt(2);
   System.out.println("The coin toss was a " + coinFlip + ".");

   if (userGuess == coinFlip) {
     System.out.println("You guessed right!");
     correctGuesses++;
   } else {
     System.out.println("Sorry, try again next time!");
   }

   // Trial 5
   System.out.println("\nWhat is your guess for trial #5?");
   userGuess = scanner.nextInt();
   coinFlip = random.nextInt(2);
   System.out.println("The coin toss was a " + coinFlip + ".");

   if (userGuess == coinFlip) {
     System.out.println("You guessed right!");
     correctGuesses++;
   } else {
     System.out.println("Sorry, try again next time!");
   }
   
   //Trials are over, final result is printed. 
   System.out.println("\nYou guessed correctly " + correctGuesses + 
     " out of 5 times (" + ((int)(correctGuesses / 5.0 * 100)) + "%).");
   
   //Closing the scanner. 
   scanner.close();
  }
}

Answer 1

首先，您只使用变量种子一次，因此您可以内联它。

int seed = scanner.nextInt();
Random random = new Random(seed);
// Replace with
Random random = new Random(scanner.nextInt());

接下来，您将获得以下区块五次：

System.out.println("\nWhat is your guess for trial #1?");
userGuess = scanner.nextInt();
coinFlip = random.nextInt(2);
System.out.println("The coin toss was a " + coinFlip + ".");

if (userGuess == coinFlip) {
  System.out.println("You guessed right!");
  correctGuesses++;
} else {
  System.out.println("Sorry, try again next time!");
}

您可以将其替换为循环或方法。 或者，我最喜欢的，两者都使用！ 所以类似：

public void simulateToss(int tossNr) {
  System.out.println("\nWhat is your guess for trial #%d?".formatted(tossNr));
  userGuess = scanner.nextInt();
  coinFlip = random.nextInt(2);
  System.out.println("The coin toss was a " + coinFlip + ".");

  if (userGuess == coinFlip) {
    System.out.println("You guessed right!");
    correctGuesses++;
  } else {
    System.out.println("Sorry, try again next time!");
  }
}

我也会将（至少在这种情况下）你的prov给出的变量放入属性中。 这会让你的代码看起来更好。

所以像这样：

for(int i = 1; i <= 5; i++) {
  simulateTrial(i);
}

// simulateTrial
private void simulateTrial(int trialNr) {
  System.out.printf("\nWhat is your guess for trial #%s?%n", trialNr);
  userGuess = scanner.nextInt();
  coinFlip = random.nextInt(2);
  System.out.println("The coin toss was a " + coinFlip + ".");

  if (userGuess == coinFlip) {
    System.out.println("You guessed right!");
    correctGuesses++;
  } else {
    System.out.println("Sorry, try again next time!");
  }
}

编辑： 您还应该考虑使用 printf 和 println，而不是手动将

\n

添加到输出中并以这种方式将字符串连接在一起