java - 在连续正确回答问题 3 次/并添加方差后，我如何将程序循环回到开头

Question

我正在创建一个程序来帮助学生解决 y= m(x) + b。截至目前，我有程序来显示菜单并评估您的回答是否正确。但是，我还需要它来计算连续正确答案的数量。

• 如果尝试了 3 次正确的结束程序并输出全部正确。
• 否则，如果有 3 次尝试，则输出为提示。

我遇到的主要问题是两个(方法？)的循环。如果我的代码很糟糕，我提前道歉，与 Python 相比，我很难理解其中的方法和类。任何人的建议或提示都会非常有帮助。

到目前为止，我已经尝试添加方法，并尝试将类添加到程序的某些部分，例如

public static void user_input(int point_of_line_cross, int slip, int y_intercept, int Independent_variable) {}

和

公共(public)静态test_input() {}

但是，现在我面临范围问题以及引用某些变量的错误。

package algebra_Tutor;
import java.util.Scanner;
class AlgebraTutor {

public static void main(String[] args){
    System.out.println("Enter 1 if you would like to solve for Y?");
    System.out.println("Enter 2 if you would like to solve for M?");
    System.out.println("Enter 3 if you would like to solve for B?");
    System.out.println("Enter 4 to Quit");


    //Asks for user input
    System.out.print("Enter your selection: ");
    }

    //Creates random # for values in formula
    int y_ = point_of_line_cross;
    int m_ = slope;
    int b_ = y_intercept; 
    int x_ = independent_variable;

public static void user_input(int point_of_line_cross, int slope, int y_intercept, int independent_variable) {

            // Creates scanner for input of menu Def as menu selector
    Scanner user_Selection = new Scanner(System.in);

            //Converts user input to an integer
    int selection = user_Selection.nextInt();
    user_Selection.close();

    y_intercept = (int) (Math.floor(Math.random() * 201) - 100);
    slope = (int) Math.floor(Math.random() * 201) - 100;
    point_of_line_cross = (int) Math.floor(Math.random() * 201) - 100;
    independent_variable = (int) Math.floor(Math.random() * 201) - 100;

            //Tests what user input was, with expected output
    if (selection  == (1)) {
        System.out.println("You chose to solve for Y: ");
        System.out.println("Y = " +slope +"("+independent_variable+")"+" + "+y_intercept);
        System.out.println("Input your answer: ");
        }
    else if (selection == (2)) {
        System.out.println("You chose to solve for M: ");
        System.out.println("M = "+"("+point_of_line_cross+" - "+y_intercept+")"+" / "+independent_variable);
        System.out.println("Input your answer: ");
        }
    else if (selection == (3)) {
        System.out.println("You chose to solve for B: ");
        System.out.println("B = "+point_of_line_cross+" - "+slope+"("+independent_variable+")");
        System.out.println("Input your answer: ");
        }
    else if (selection == (4)) {
        System.out.println("You chose to quit the program. ");
    return;
        }
        }

//Solves the problem in order to compare to User input
    int answer_y = ((m_) * (x_)) + (b_);
    int answer_m =(y_) - ((b_) / (x_));
    int answer_b =(y_) - ((m_)* (x_));
public static test_input() {
        //Problem solver defined
    Scanner answer_input = new Scanner(System.in);
    int answer = answer_input.nextInt(); 
        //Creates loop for program
    var counter = 0;
    int correct = 0;
    var answers_correct = false;
    while (!answers_correct && correct < 3) {
        if (answer == answer_y){
            counter++;
            correct++;
            System.out.println("You answered correctly");
        return;
        }
        else if (counter >= 3 && correct < 3) {
            System.out.println("Youve been missing the questions lately, let me help! ");
        }
        else
        {
            System.out.println("Try again");
            counter++;
            correct = 0;
        break;
            }
        }
    }
}

我希望在用户连续完成 3 个问题后，程序能够通过尝试输出正确的答案。另外，尝试3次后需要输出提示。然后在 3 个正确之后，它应该循环回到程序的开头。

Answer 1

好吧，我想我会让你弄清楚如何让它自己循环，但我解决了你的其他问题，并在我改变的地方发表了评论。希望这有帮助

//declared variables here. global variables must be declared static when accessed in a static method (ex: user_input())
static int y_;
static int m_;
static int b_;
static int x_;

public static void main(String[] args) {
    // Creates scanner for input of menu Def as menu selector
    Scanner user_Selection = new Scanner(System.in);

    System.out.println("Enter 1 if you would like to solve for Y?");
    System.out.println("Enter 2 if you would like to solve for M?");
    System.out.println("Enter 3 if you would like to solve for B?");
    System.out.println("Enter 4 to Quit");

    //Converts user input to an integer
    int selection = user_Selection.nextInt();

    //call user_input()
    user_input(selection);


}

public static void user_input(int selection) {

    Scanner user_Selection = new Scanner(System.in);
    int userAnswer;
    int y_intercept = (int) (Math.floor(Math.random() * 201) - 100);
    int slope = (int) Math.floor(Math.random() * 201) - 100;
    int point_of_line_cross = (int) Math.floor(Math.random() * 201) - 100;
    int independent_variable = (int) Math.floor(Math.random() * 201) - 100;

    y_ = point_of_line_cross;
    m_ = slope;
    b_ = y_intercept;
    x_ = independent_variable;


    //Tests what user input was, with expected output
    if (selection == (1)) {
        System.out.println("You chose to solve for Y: ");
        System.out.println("Y = " + slope + "(" + independent_variable + ")" + " + " + y_intercept);
        System.out.println("Input your answer: ");
        userAnswer = user_Selection.nextInt();
        /*After user enters answer we test the answer by calling test_input
         * */
       test_input(userAnswer);
    } else if (selection == (2)) {
        System.out.println("You chose to solve for M: ");
        System.out.println("M = " + "(" + point_of_line_cross + " - " + y_intercept + ")" + " / " + independent_variable);
        System.out.println("Input your answer: ");
        userAnswer = user_Selection.nextInt();
        /*After user enters answer we test the answer by calling test_input
         * */
        test_input(userAnswer);
    } else if (selection == (3)) {
        System.out.println("You chose to solve for B: ");
        System.out.println("B = " + point_of_line_cross + " - " + slope + "(" + independent_variable + ")");
        System.out.println("Input your answer: ");
        userAnswer = user_Selection.nextInt();
        /*After user enters answer we test the answer by calling test_input
         * */
        test_input(userAnswer);
    } else if (selection == (4)) {
        System.out.println("You chose to quit the program. ");
    }
}

// you forgot to include return type ex: void, int, String, double, float, etc
public static void test_input(int entered_answer) {
    //Solves the problem in order to compare to User input
    int answer_y = ((m_) * (x_)) + (b_);
    int answer_m = (y_) - ((b_) / (x_));
    int answer_b = (y_) - ((m_) * (x_));

    //Problem solver defined
    int answer = entered_answer;

    //Creates loop for program
    int counter = 0;
    int correct = 0;
    boolean answers_correct = false;

    while (!answers_correct && correct < 3) {
        if (answer == answer_y) {
            counter++;
            correct++;
            System.out.println("You answered correctly");
            return;
        } else if (counter >= 3 && correct < 3) {
            System.out.println("You've been missing the questions lately, let me help! ");
        } else {
            System.out.println("Try again");
            counter++;
            correct = 0;
            break;
        }
    }

}

`

public static void user_input(int point_of_line_cross, int slope, int y_intercept, int independent_variable)

如果您给方法提供参数，那么当调用该方法时，您必须自己将值输入到参数中。我认为这不是您想要的，因为您在此处定义了您想要的参数值:

y_intercept = (int) (Math.floor(Math.random() * 201) - 100);
slope = (int) Math.floor(Math.random() * 201) - 100;
point_of_line_cross = (int) Math.floor(Math.random() * 201) - 100;
independent_variable = (int) Math.floor(Math.random() * 201) - 100;

在你的 test_input() 方法中你写道:

Scanner answer_input = new Scanner(System.in);
int answer = answer_input.nextInt();

.nextInt() 将使程序停止并等待用户输入，因此在准备好获取输入之前您不想使用它。

我对java中的var关键字了解不多，但我认为你应该声明变量类型，而不是使用var，因此:

var counter = 0;

对此:

int counter = 0;

为了更好地了解方法的工作原理，我推荐这两个视频: Intro to java methods Java method parameters and return types

要深入了解 Java 的基础知识，我推荐整个播放列表 Java Beginner Programming