我制作了一个Java程序，为小学生做了一些基本的数学运算。我想让它更先进，并记住他们出错的问题，然后选择在最后再次提出这些问题并让他们再次尝试。
但是它的代码非常复杂。我以为我完成了它，但它编译有困难（阅读：不会），我正处于需要帮助的地步。我非常感激。
import java.util.Scanner;
import java.util.Random;
public class ArithmeticTester0 {
public static void main(String[] arg) {
int level = 0;
String type = "";
String name = "";
Scanner keyboard = new Scanner(System.in);
System.out.println("Hi! I am your friendly Math Tutor.");
System.out.print("What is your name? ");
name = keyboard.nextLine();
System.out.print("Would you like to be tested on addition, subtraction or both? ");
type = keyboard.nextLine();
// Check if the type inputted is anything other than addition, subtraction or both
if (!type.equalsIgnoreCase("addition") && !type.equalsIgnoreCase("subtraction") && !type.equalsIgnoreCase("both") && !type.equalsIgnoreCase("add") && !type.equalsIgnoreCase("subtraction")) {
while (!type.equalsIgnoreCase("addition") && !type.equalsIgnoreCase("subtraction") && !type.equalsIgnoreCase("both") && !type.equalsIgnoreCase("add") && !type.equalsIgnoreCase("subtraction")) {
System.out.print("You must answer addition, subtraction or both. How about we try again? ");
type = keyboard.nextLine();
}
}
System.out.print("What level would you like to choose? " +
" Enter 1, 2 or 3: ");
level = keyboard.nextInt();
// Check if the level entered is not 1, 2 or 3
if (level > 3 || level < 1) {
while (level > 3 || level < 1) {
System.out.println("The number must be either 1, 2 or" +
" 3. Let's try again shall we?");
System.out.print("What level would you like to choose? ");
level = keyboard.nextInt();
}
}
System.out.println("\nOK " + name +
", here are 10 exercises for you at level " + level + ".");
System.out.println("Good luck!\n");
int a = 0, b = 0, c = 0;
int preva = 0, prevb = 0; //previous a and b value
int correct = 0;
if (type.equalsIgnoreCase("addition") || type.equalsIgnoreCase("add")) {
add(level, preva, prevb, a, b, c, type);
}
else if (type.equalsIgnoreCase("subtraction") || type.equalsIgnoreCase("subtract")) {
subtract(level, preva, prevb, a, b, c, type);
}
else {
both(level, preva, prevb, a, b, c, type);
}
}
/* The method below prints out a statement depending
on how well the child did */
public static void add(int level, int preva, int prevb, int a, int b, int c, String type) {
Random random = new Random();
Scanner keyboard = new Scanner(System.in);
List<Integer> wrongList = Arrays.asList(array);
int correct = 0;
int wrong = 0;
// Generate 10 questions
for (int i = 1; i <= 10; i++) {
/* Generate numbers depending on the difficulty.
The while loop ensures that the next question isn't the same
as the previous question that was just asked. */
if (level == 1) {
while (preva == a && prevb == b) {
a = random.nextInt(10);
b = random.nextInt(11-a);
}
}
else if (level == 2) {
while (preva == a && prevb == b) {
a = random.nextInt(10);
b = random.nextInt(10);
}
}
else if (level == 3) {
while (preva == a && prevb == b) {
a = random.nextInt(50);
b = random.nextInt(50);
}
}
preva = a;
prevb = b;
System.out.print(a + " + " + b + " = ");
c = keyboard.nextInt();
// Check if the user was correct
if (a + b == c) {
System.out.println("You are right!");
correct++;
}
if (a - b != c) {
wrongList.add(a);
wrongList.add(b);
wrong++;
}
}
// Conclusion
System.out.println("\nYou got " + correct + " right out of 10.");
if (wrong > 0) {
int[] wrongAnswers = wrongList.toArray(new int[wrongList.size()]);
System.out.print("You got " + wrong + " wrong, would you like to retry those questions?");
String response = keyboard.nextLine();
if (response.equalsIgnoreCase("Yes") || response.equalsIgnoreCase("Okay") || response.equalsIgnoreCase("OK") || response.equalsIgnoreCase("Sure") || response.equalsIgnoreCase("Yeah") || response.equalsIgnoreCase("Yea")) {
retry(wrongAnswers, type, wrongIndexArray);
}
else if (response.equalsIgnoreCase("No") || response.equalsIgnoreCase("Nope") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("No thanks") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("Do not want")) {
System.out.println("OK! That's fine.");
}
else {
while (response.equalsIgnoreCase("Yes") || response.equalsIgnoreCase("Okay") || response.equalsIgnoreCase("OK") || response.equalsIgnoreCase("Sure") || response.equalsIgnoreCase("Yeah") || response.equalsIgnoreCase("Yea") || response.equalsIgnoreCase("No") || response.equalsIgnoreCase("Nope") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("No thanks") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("Do not want")) {
System.out.println("Please put in an answer that is along the lines of \"yes\" or \"no\".");
response = keyboard.nextLine();
}
}
}
conclusion(correct, level);
System.out.println("See ya!");
}
public static void subtract(int level, int preva, int prevb, int a, int b, int c, String type) {
Random random = new Random();
Scanner keyboard = new Scanner(System.in);
List<Integer> wrongList = Arrays.asList(array);
// Generate 10 questions
int correct = 0;
int wrong = 0;
for (int i = 1; i <= 10; i++) {
/* Generate numbers depending on the difficulty.
The while loop ensures that the next question isn't the same
as the previous question that was just asked. */
if (level == 1) {
while (preva == a && prevb == b) {
a = random.nextInt(10);
b = random.nextInt(11-a);
while (b > a) {
a = random.nextInt(10);
b = random.nextInt(11-a);
}
}
}
else if (level == 2) {
while (preva == a && prevb == b) {
a = random.nextInt(10);
b = random.nextInt(10);
while (b > a) {
a = random.nextInt(10);
b = random.nextInt(11-a);
}
}
}
else if (level == 3) {
while (preva == a && prevb == b) {
a = random.nextInt(50);
b = random.nextInt(50);
}
}
preva = a;
prevb = b;
System.out.print(a + " - " + b + " = ");
c = keyboard.nextInt();
// Check if the user was correct
if (a - b == c) {
System.out.println("You are right!");
correct++;
}
if (a - b != c) {
wrongList.add(a);
wrongList.add(b);
wrong++;
}
}
// Conclusion
System.out.println("\nYou got " + correct + " right out of 10.");
if (wrong > 0) {
int[] wrongAnswers = wrongList.toArray(new int[wrongList.size()]);
System.out.print("You got " + wrong + " wrong, would you like to retry those questions?");
String response = keyboard.nextLine();
if (response.equalsIgnoreCase("Yes") || response.equalsIgnoreCase("Okay") || response.equalsIgnoreCase("OK") || response.equalsIgnoreCase("Sure") || response.equalsIgnoreCase("Yeah") || response.equalsIgnoreCase("Yea")) {
retry(wrongAnswers, type);
}
else if (response.equalsIgnoreCase("No") || response.equalsIgnoreCase("Nope") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("No thanks") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("Do not want")) {
System.out.println("OK! That's fine.");
}
else {
while (response.equalsIgnoreCase("Yes") || response.equalsIgnoreCase("Okay") || response.equalsIgnoreCase("OK") || response.equalsIgnoreCase("Sure") || response.equalsIgnoreCase("Yeah") || response.equalsIgnoreCase("Yea") || response.equalsIgnoreCase("No") || response.equalsIgnoreCase("Nope") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("No thanks") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("Do not want")) {
System.out.println("Please put in an answer that is along the lines of \"yes\" or \"no\".");
response = keyboard.nextLine();
}
}
}
conclusion(correct, level);
System.out.println("See ya!");
}
public static void both(int level, int preva, int prevb, int a, int b, int c, String type) {
Random random = new Random();
Scanner keyboard = new Scanner(System.in);
// Generate 10 questions
int correct = 0;
List<Integer> wrongIndexes = Arrays.asList(array);
for (int i = 1; i <= 5; i++) {
/* Generate numbers depending on the difficulty.
The while loop ensures that the next question isn't the same
as the previous question that was just asked. */
if (level == 1) {
while (preva == a && prevb == b) {
a = random.nextInt(10);
b = random.nextInt(11-a);
}
}
else if (level == 2) {
while (preva == a && prevb == b) {
a = random.nextInt(10);
b = random.nextInt(10);
}
}
else if (level == 3) {
while (preva == a && prevb == b) {
a = random.nextInt(50);
b = random.nextInt(50);
}
}
preva = a;
prevb = b;
System.out.print(a + " + " + b + " = ");
c = keyboard.nextInt();
// Check if the user was correct
if (a + b == c) {
System.out.println("You are right!");
correct++;
}
else {
System.out.println("Oops! You made a mistake. " + a + " + " + b + " = " + (a+b));
wrongIndexes += i;
}
}
for (int i = 6; i <= 10; i++) {
/* Generate numbers depending on the difficulty.
The while loop ensures that the next question isn't the same
as the previous question that was just asked. */
if (level == 1) {
while (preva == a && prevb == b) {
a = random.nextInt(10);
b = random.nextInt(11-a);
while (b > a) {
a = random.nextInt(10);
b = random.nextInt(11-a);
}
}
}
else if (level == 2) {
while (preva == a && prevb == b) {
a = random.nextInt(10);
b = random.nextInt(10);
while (b > a) {
a = random.nextInt(10);
b = random.nextInt(11-a);
}
}
}
else if (level == 3) {
while (preva == a && prevb == b) {
a = random.nextInt(50);
b = random.nextInt(50);
}
}
preva = a;
prevb = b;
System.out.print(a + " - " + b + " = ");
c = keyboard.nextInt();
// Check if the user was correct
if (a - b == c) {
System.out.println("You are right!");
correct++;
}
else {
System.out.println("Oops! You made a mistake. " + a + " - " + b + " = " + (a-b));
wrongIndexes += i;
}
}
int[] wrongIndexArray = wrongIndexes.toArray(new int[wrongIndexes.size()]);
// Conclusion
System.out.println("\nYou got " + correct + " right out of 10.");
if (wrong > 0) {
int[] wrongAnswers = wrongList.toArray(new int[wrongList.size()]);
System.out.print("You got " + wrong + " wrong, would you like to retry those questions?");
String response = keyboard.nextLine();
if (response.equalsIgnoreCase("Yes") || response.equalsIgnoreCase("Okay") || response.equalsIgnoreCase("OK") || response.equalsIgnoreCase("Sure") || response.equalsIgnoreCase("Yeah") || response.equalsIgnoreCase("Yea")) {
retry(wrongAnswers, type, wrongIndexArray);
}
else if (response.equalsIgnoreCase("No") || response.equalsIgnoreCase("Nope") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("No thanks") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("Do not want")) {
System.out.println("OK! That's fine.");
}
else {
while (response.equalsIgnoreCase("Yes") || response.equalsIgnoreCase("Okay") || response.equalsIgnoreCase("OK") || response.equalsIgnoreCase("Sure") || response.equalsIgnoreCase("Yeah") || response.equalsIgnoreCase("Yea") || response.equalsIgnoreCase("No") || response.equalsIgnoreCase("Nope") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("No thanks") || response.equalsIgnoreCase("Nah") || response.equalsIgnoreCase("Do not want")) {
System.out.println("Please put in an answer that is along the lines of \"yes\" or \"no\".");
response = keyboard.nextLine();
}
}
}
conclusion(correct, level);
System.out.println("See ya!");
}
public static void retry(int[] wrongAnswers, String type, int[] wrongIndexArray) {
int c = 0;
if (type.equalsIgnoreCase("addition") || type.equalsIgnoreCase("add")) {
for (int i = 0; i < wrongAnswers.length; i+=2) {
System.out.print(wrongAnswers[i] + " + " + wrongAnswers[i+1] + " = ");
c = keyboard.nextInt();
if (wrongAnswers[i] + wrongAnswers[i+1] == c) {
System.out.println("You are right!");
}
else {
System.out.println("Oops! You made a mistake. " + wrongIndex[i] + " + " + wrongIndex[i+1] + " = " + (wrongIndex[i]+wrongIndex[i+1]));
}
}
}
else if (type.equalsIgnoreCase("subtraction") || type.equalsIgnoreCase("subtract")) {
for (int i = 0; i < wrongAnswers.length; i+=2) {
System.out.print(wrongAnswers[i] + " - " + wrongAnswers[i+1] + " = ");
c = keyboard.nextInt();
if (wrongAnswers[i] - wrongAnswers[i+1] == c) {
System.out.println("You are right!");
}
else {
System.out.println("Oops! You made a mistake. " + a + " - " + b + " = " + (a-b));
}
}
}
else {
for (int i = 0; i < wrongAnswers.length; i+=2) {
for (int i = 0; i < wrongIndexArray.length; i++) {
if (wrongIndexArray[i] < 6) {
System.out.print(wrongAnswers[i] + " + " + wrongAnswers[i+1] + " = ");
c = keyboard.nextInt();
if (wrongAnswers[i] + wrongAnswers[i+1] == c) {
System.out.println("You are right!");
}
else {
System.out.println("Oops! You made a mistake. " + wrongIndex[i] + " + " + wrongIndex[i+1] + " = " + (wrongIndex[i]+wrongIndex[i+1]));
}
}
else if (wrongIndexArray[i] > 5) {
System.out.print(wrongAnswers[i] + " - " + wrongAnswers[i+1] + " = ");
c = keyboard.nextInt();
if (wrongAnswers[i] - wrongAnswers[i+1] == c) {
System.out.println("You are right!");
}
else {
System.out.println("Oops! You made a mistake. " + wrongIndex[i] + " + " + wrongIndex[i+1] + " = " + (wrongIndex[i]+wrongIndex[i+1]));
}
}
}
}
}
}
public static void conclusion(int x, int lev) {
if (x >= 9) {
if (lev == 3) {
if (x == 9)
System.out.println("Please try the same difficulty again" +
", you almost scored 10 out of 10!");
else
System.out.println("You have mastered addition at this level" +
"! The system is not of any further use.");
}
else {
System.out.println("Please select a higher difficulty next time!");
}
}
else if (x >= 6) {
System.out.println("Please try the test again.");
}
else {
System.out.println("Please ask your teacher for extra lessons.");
}
}
}
答案 0 :(得分：3)
错误是：
您忘记导入java.util.List。只需继续导入java.util。*。你知道你想要的。
您没有在任何地方声明wrongIndexArray，array，wrong，wrongList，keyboard，a或b。我可能错过了一些。
在这一行：
int[] wrongAnswers = wrongList.toArray(new int[wrongList.size()]);
wrongList是List<Integer>所以我认为你不能将它转换为int []。你必须使用Integer []。
可能是其他人，但是......
...基于您所遇到的错误，您使用的是NetBeans等IDE吗？使用IDE可以帮助您确定出现错误的原因，并且它们通常包含每个错误的有用提示。
其他一些有用的提示：
当学生得到错误答案时，您似乎将操作数存储在列表中。考虑将操作数和操作包装成一个类，例如SubtractionQuestion或AdditionQuestion。如果你想重新测试那些错误的学生，这可能会有所帮助。
将“是”和“否”文本答案（是的，是的，是的，是的）存储在ArrayList＆lt; String＆gt;中。 yesAnswers，然后检查yesAnswers.contains（回答）。这样可以很容易地维护列表，而且你也不需要检查是，否，或者不是是或否 - 只需检查是，否则否，否则回答错误。
希望有道理......