Question

如果您需要任何解释，请随时提出。 EquationsAndAnswers类的目标是生成8个数组，4个字符串类型和4个double类型，并使用加法公式填充它们，然后为每个基本数学运算符求答等等。然后，从这8个阵列中，应该从四个弦类型方程阵列中的任何一个中随机选择一个方程式。选择随机方程式和要写入的相应答案后，将它们写入文件（equations.txt）。我的问题是，在从Menu类调用writeBoth方法之后，equations.txt文件看起来像这样：

而不是像这样：

1+2

3-2

4*5

10÷2

我的课程菜单：

public class Menu {

    public static boolean additionBool = true;
    public static boolean subtractionBool = true;
    public static boolean multiplicationBool = true;
    public static boolean divisionBool = true;
    public static boolean doubleDigitBool = false;

    new EquationsAndAnswers().writeBoth();  
}

我的类EquationsAndAnswers：

import java.util.Random;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

import javax.swing.JOptionPane;

public class EquationsAndAnswers {
/*Random Generators*/
    Random singleDigitNaturalGen = new Random();
    Random randomEquationPicker = new Random();
    Random doubleDigitNaturalGen = new Random();
public void writeBoth(){    



    /*Declaration of Four Basic Mathematic Operation Equation Arrays and Corresponding Answers*/
    String additionArrayEquation[] = new String[100];
    int additionArrayAnswers[] = new int[100];

    String subtractionArrayEquation[] = new String[100];
    int subtractionArrayAnswers[] = new int[100];

    String multiplicationArrayEquation[] = new String[100];
    int multiplicationArrayAnswers[] = new int[100];

    String divisionArrayEquation[] = new String[100];
    double divisionArrayAnswers[] = new double[100];

    String assortedEquations[] = new String[100];
    double assortedAnswers[] = new double[100];

    /*Population of Basic Operation Equation Arrays*/
    /*Population of Addition Equation and Answer Arrays*/
    for(int additionArrayGenerationX = 0; additionArrayGenerationX < additionArrayEquation.length; additionArrayGenerationX++){

        int tempAdditionY = singleDigitNaturalGen.nextInt(11), tempAdditionX = singleDigitNaturalGen.nextInt(11);
        int answer = tempAdditionY + tempAdditionX;
        String equation = (tempAdditionY + " + " + tempAdditionX); 
        additionArrayEquation[additionArrayGenerationX] = equation;
        additionArrayAnswers[additionArrayGenerationX] = answer;
    }



    /*Population of Subtraction Equation and Answer Arrays*/
    for(int subtractionArrayGenerationX = 0; subtractionArrayGenerationX < subtractionArrayEquation.length; subtractionArrayGenerationX++){

        int tempSubtractionY = singleDigitNaturalGen.nextInt(11), tempSubtractionX = singleDigitNaturalGen.nextInt(11);
        int answer = tempSubtractionY - tempSubtractionX;
        String equation = (tempSubtractionY + " - " + tempSubtractionX); 
        subtractionArrayEquation[subtractionArrayGenerationX] = equation;

        subtractionArrayAnswers[subtractionArrayGenerationX] = answer;
    }


    /*Population of Multiplication Equation and Answer Arrays*/
    for(int multiplicationArrayGenerationX = 0; multiplicationArrayGenerationX < multiplicationArrayEquation.length; multiplicationArrayGenerationX++){

        int tempMultiplicationY = singleDigitNaturalGen.nextInt(11), tempMultiplicationX = singleDigitNaturalGen.nextInt(11);
        int answer = tempMultiplicationY*tempMultiplicationX;
        String equation = ""; 
        multiplicationArrayEquation[multiplicationArrayGenerationX] = equation;

        multiplicationArrayAnswers[multiplicationArrayGenerationX] = answer;
    }



    /*Population of Division Equation and Answer Arrays*/
    for(int divisionArrayGenerationX = 0; divisionArrayGenerationX < divisionArrayEquation.length; divisionArrayGenerationX++){

        int tempDivisionY = singleDigitNaturalGen.nextInt(11), tempDivisionX = singleDigitNaturalGen.nextInt(11);
        double answer = ((double)tempDivisionY / (double)tempDivisionX);
        String equation = ""; 
        divisionArrayEquation[divisionArrayGenerationX] = equation;

        divisionArrayAnswers[divisionArrayGenerationX] = answer;
    }



    /*Deciding on Equations to be displayed.*/
    int i = 0;

    System.out.println(additionArrayEquation[0]);//dev

    /*This puts the equations in a random order in the assortedEquations array, in preparation to be written to the Equations.txt file*/        
    for(int epsilon = 0; epsilon < assortedEquations.length; epsilon++){    

        int equationType = randomEquationPicker.nextInt(4);

        if(equationType == 0){
            if(Menu.additionBool = true){
                assortedEquations[epsilon] = additionArrayEquation[i];
                assortedAnswers[epsilon] = additionArrayAnswers[i];
            }
            else{
                assortedEquations[epsilon] = "Bonus: Enter 0";
            }
        }

        else if(equationType == 1){
            if(Menu.subtractionBool = true){
                assortedEquations[epsilon] = subtractionArrayEquation[i];
                assortedAnswers[epsilon] = subtractionArrayAnswers[i];
            }

            else{
                assortedEquations[epsilon] = "Bonus: Enter 0";
            }
        }
        else if(equationType == 2){
            if(Menu.multiplicationBool = true){         
                assortedEquations[epsilon] = multiplicationArrayEquation[i];
                assortedAnswers[epsilon] = multiplicationArrayAnswers[i];
            }
            else{
                assortedEquations[epsilon] = "Bonus: Enter 0";
            }
        }   
        else{
            if(Menu.divisionBool = true){
                assortedEquations[epsilon] = divisionArrayEquation[i];
                assortedAnswers[epsilon] = divisionArrayAnswers[i];
            }
            else{
                assortedEquations[epsilon] = "Bonus: Enter 0";
            }
        }
    }


    /*Writing each equation to the file.*/
    try {
        BufferedWriter writeEquation = new BufferedWriter(new FileWriter("Equations.txt"));
        BufferedWriter writeAnswer = new BufferedWriter(new FileWriter("Answers.txt"));

        for(int theta = 0; theta < assortedEquations.length; theta++){
            writeEquation.write(assortedEquations[theta]+ "\n");
            writeAnswer.write(assortedAnswers[theta] + "\n");
        }



        writeEquation.close();
        writeAnswer.close();
    } catch (IOException e) {JOptionPane.showMessageDialog(null, "Whoops, there seems to have been an error. Sorry about that.");}
}
}

Answer 1

如果不运行此功能，我认为您只是"Bonus: Enter 0"？

if(Menu.subtractionBool = true)
if(Menu.subtractionBool == true)

这两行之间存在着天壤之别。

Answer 2

我弄明白了这个问题。我的旧代码是：

int tempDivisionY = singleDigitNaturalGen.nextInt(11), tempDivisionX = singleDigitNaturalGen.nextInt(11);
double answer = ((double)tempDivisionY / (double)tempDivisionX);
String equation = "";

应该说：

String equation = tempDivisionY + " / " + tempDivisionX;

写入文件时，它会写入相同的整数而不是不同的整数

2 个答案: