【发布时间】：2014-04-12 00:06:57
【问题描述】：
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 个双精度类型，并用加法方程填充它们，然后为每个基本数学运算符提供答案等。然后，从这 8 个数组中，它应该从四个字符串类型方程数组中的任何一个中随机选择方程，一次一个。在选择要写入的随机方程和相应的答案后，将它们写入文件（equations.txt）。 我的问题是，我从 Menu 类调用 writeBoth 方法后， equations.txt 文件如下所示：
6 + 10
6 + 10
8 - 9
8 - 9
6 + 10
8 - 9
6 + 10
而不是这样：
1+2
3-2
4*5
10÷2
我的班级菜单：
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();
}
我的课 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.");}
}
}
【问题讨论】：
-
"If you need any explanation, please feel free to ask..."-- 是的，请解释您的代码和问题。细节很重要。 -
我添加了一些关于我的代码功能的更多细节，我无法更好地解释这个问题，因为我不知道我为什么会遇到它。对不起。
-
我将删除我对附加信息的否决票，希望你能很快得到一个体面的答案，但至于我，我将等待更多信息，包括更详细的解释您当前的代码，包括方法应该做什么。此外，您尝试调试代码（包括使用调试器）向您展示了什么？
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我已经尝试注释掉它随机选择要添加到 assortedEquations 数组中的方程的部分，并且只打印每个单独的方程和答案数组，方程和答案似乎工作正常，所以它必须位于代码块中的某个位置，从注释“/*这将方程以随机顺序放入 assortedEquations 数组中，以准备写入 Equations.txt 文件*/”。此外，我已经删除了我认为无用的大部分代码，因为它只是使用两位数的相同内容，我还没有使用过。
标签： java for-loop file-io random