不使用方法返回java程序的主菜单

我目前是一名编程新手。我们的任务是评估用于两个矩阵的行和列是否可以执行加法操作。如果无效，我们将显示适当的消息，并通过询问用户是否重复该过程来重复该过程。如果答案为否，则控件应返回主菜单。我们当时不允许使用方法，所以我对此很有疑问

import java.util.Scanner;
public class matrixTransposition {
public static void main(String[] args) {
    Scanner src = new Scanner(System.in);

    int menu_choice;
    char case_choice;
    char case_choice2;
    boolean menu_repeat = true;
    boolean case_repeat = true;
    boolean check = true;
    boolean inCheck = true;
    int rows_A, columns_A;
    int rows_A2, columns_A2;

    int rows_S, columns_S;
    int rows_M, columns_M;


do{
        //main menu selection here
    
    
        System.out.print("\nEnter your choice: ");
        menu_choice = src.next().charAt(0);

    
        switch(menu_choice){
            case '1':
            
            do{
                System.out.println("-------------------------------------------------");
                System.out.println("\t\tMatrix Addition");
                
                //First Matrix/Array

                System.out.print("\nFirst Matrix: Please enter number of rows: "); //asks the user to enter number of rows
                rows_A = src.nextInt(); 
                
                System.out.print("\nFirst Matrix: Please enter number of columns: "); //asks the user to enter number of columns
                columns_A = src.nextInt();

                int [][] firstMatrix_A = new int [rows_A][columns_A];
                int [][] secondMatrix_A = new int [rows_A][columns_A]; //declaring the arrays to be used
                int [][] sumMatrix_A = new int [rows_A][columns_A];

                //asks the user to enter values
                System.out.println("\nPlease enter values for first matrix: ");
                for(int i=0; i<rows_A; i++)
                    for(int j=0; j<columns_A; j++)
                    firstMatrix_A[i][j]=src.nextInt();

                //--------------------------------------------------------------------------------
                //--------------------------------------------------------------------------------
                
                //Second Matrix/Array
                do{
                    System.out.println("------------------------------------");
                    System.out.print("Second Matrix: Please enter number of rows: "); // asks the user to enter rows
                    rows_A2 = src.nextInt(); 
                    
                    System.out.print("\nSecond Matrix: Please enter number of columns: "); //asks the user to enter columns
                    columns_A2 = src.nextInt();

                    //validating if the 2nd matrix has the same length as the first matrix
                    if(rows_A2 != rows_A || columns_A2 != columns_A){
                        System.out.println("------------------------------------");
                        System.out.println("Error! Input is not the same length as the First Matrix!");
                        System.out.print("Do you want to input again? [Y][N]: ");
                        case_choice2 = src.next().charAt(0);
                        
                        switch(case_choice2){
                            case 'Y':
                                check = true;   //if the user entered Y, the user would be able  
                                break;          //re-enter rows and columns for the 2nd matrix
                            case 'N':
                                check = false;          //if the user entered N, the user would be immediately brought
                                menu_repeat = true;      //back to the main menu selection
                                break;
                            case 'y':
                                check = true;       //if the user entered Y, the user would be able
                                break;              //re-enter rows and columns for the 2nd matrix
                            case 'n':
                                menu_repeat = true;     //if the user entered N, the user would be immediately brought
                                check = false;          //back to the main menu selection
                                break;      
                            default:                    //if the user did not enter Y or N, the user would be ask to
                                                        //enter again.
                                System.out.println("---------------------------------------------");
                                System.out.println("Invalid Input Please Try Again....");
            
                            while(case_repeat){
                                System.out.println("---------------------------------------------");
                                System.out.print("Try Again? [Y][N]: ");
                                case_choice2 = src.next().charAt(0);
            
                                switch(case_choice2){
                                    case 'Y':
                                        check = true;               //if the user entered Y, the user would be able 
                                        case_repeat = false;        //re-enter rows and columns for the 2nd matrix
                                        break;
                                    case 'N':
                                        check = false;               //if the user entered N, the user would be immediately brought
                                        case_repeat = false;         //back to the main menu selection
                                        menu_repeat = true;
                                        break;
                                    case 'y':
                                        check = true;                //if the user entered y, the user would be able
                                        case_repeat = false;          //re-enter rows and columns for the 2nd matrix
                                        break;
                                    case 'n':
                                        check = false;              //if the user entered n, the user would be immediately brought
                                        case_repeat = false;        //back to the main menu selection
                                        menu_repeat = true;
                                        break;
                                    default:                        //if the user did not enter Y or N, the user would be ask to
                                                                    //enter again.
                                        System.out.println("---------------------------------------------");
                                        System.out.println("Invalid Input Please Try Again....");
                                        case_repeat = true;
                                }
                            }
                        }      
                    }
                        //else if all inputs are valid the program would proceed to the next step
                    else{
                    
                    //asks the user to enter values
                    System.out.println("\nPlease enter values for second matrix: ");
                    for(int i=0; i<rows_A2; i++)
                        for(int j=0; j<columns_A2; j++)
                            secondMatrix_A[i][j]=src.nextInt();
                            check = false;
                    }
                }while(check);
            
                //--------------------------------------------------------------------------------
                //--------------------------------------------------------------------------------

                for(int i=0; i<rows_A; i++)
                for(int j=0; j<columns_A; j++)
                sumMatrix_A[i][j] = firstMatrix_A[i][j] + secondMatrix_A[i][j]; //adds the two matrices

                System.out.println("------------------------------------");     //displays the first matrix
                System.out.println("First Matrix");
                for(int i=0; i<rows_A; i++){
                    for(int j=0; j<columns_A; j++){
                        System.out.print(firstMatrix_A[i][j] + "  ");    
                    }
                    System.out.println();
                }

                System.out.println("------------------------------------");     //displays the second matrix
                System.out.println("Second Matrix");
                for(int x=0; x<rows_A2; x++){
                    for(int y=0; y<columns_A2; y++){
                        System.out.print(secondMatrix_A[x][y] + "  ");    
                    }
                    System.out.println();
                }

                System.out.println("------------------------------------");     //displays the sum of the two matrices
                System.out.println("Matrix Sum");
                for(int i=0; i<rows_A; i++){
                    for(int j=0; j<columns_A; j++){
                        System.out.print(sumMatrix_A[i][j] + "  ");    
                    }
                    System.out.println();
                }
                
                System.out.print("Do you want to try again? [Y][N]: ");         //asks the user to re-run the operation
                case_choice = src.next().charAt(0);
            }while(case_choice == 'Y' || case_choice == 'y');                   //if yes the operation would re-run
            
            if(case_choice == 'N' || case_choice == 'n'){                       //if no, the user would be brought back to the
                menu_repeat = true;                                             //main menu selection
            }
        
            break;
             }

          }while(menu_repeat); 
       }
      }  

import java.util.Scanner；
公共类矩阵传输{
公共静态void main（字符串[]args）{
扫描仪src=新扫描仪（System.in）；
int菜单选项；
char case_选择；
char case_choice2；
布尔菜单_repeat=true；
布尔case_repeat=true；
布尔检查=真；
布尔inCheck=true；
int行_A，列_A；
int行_A2，列_A2；
int行、列；
int行_M，列_M；
做{
//主菜单选择在这里
System.out.print（“\n输入您的选择：”）；
menu_choice=src.next（）.charAt（0）；
开关（菜单选择）{
案例“1”：
做{
System.out.println（“-------------------------------------------------------------”；
System.out.println（“\t\t矩阵添加”）；
//第一矩阵/阵列
System.out.print（“\n第一个矩阵：请输入行数：”）；//要求用户输入行数
行A=src.nextInt（）；
System.out.print（“\n第一个矩阵：请输入列数：”）；//要求用户输入列数
columns_A=src.nextInt（）；
int[]firstMatrix\u A=新int[行\u A][列\u A]；
int[]secondMatrix_A=new int[rows_A][columns_A]；//声明要使用的数组
int[]sumMatrix_A=新int[行_A][列_A]；
//要求用户输入值
System.out.println（“\n请为第一个矩阵输入值：”）；
对于（int i=0；i而言，问题在于当用户输入N时，您正在跳出内部循环。您想要的是跳出显示菜单选项的循环，即最外层的循环

您的代码结构如下所示：

do{
    //main menu selection here
    switch (menu_choice) {
            case '1':
                do {
                    //First Matrix/Array
                    //Second Matrix/Array
                    do {
                        //compare matrix and prompt for input if rows and col dont match
                        case_choice2 = src.next().charAt(0);

                        switch (case_choice2) {
                            case 'N':
                            check = false;
                            menu_repeat = true;
                            break;
                            .
                            .
                            .
                         }
                   }
            }
       }
}

您的break语句从内部循环中断。而您希望中断到最外层的循环

为此，应使用标签：

do{
        //main menu selection here
        //define label here
        main_menu:
        switch (menu_choice) {

            .
            .
            .
                 switch (case_choice2) {
                                case 'N':
                                check = false;
                                menu_repeat = true; 
                                //label used here
                                break main_menu;

            .
            .
            .

这将跳转到您选择的循环。如果要将控件传递回循环，也可以使用“继续”

请注意：你可能想重新考虑CaseYORY变量的用法，因为它将不再总是在循环外访问，因为你正在破解它。编译器肯定会给你同样的错误。
你在哪里被卡住了，你有什么错误吗？我得到一个错误。当用户输入字符N时，用户必须返回主菜单。但在我的情况下，它仍然会继续执行代码，并给我一个错误Hi@Ivy，你能用这些信息编辑帖子以使你的帖子更清晰吗？@Sergio，我在这里添加了一些注释来解释每个函数。我得到的错误在swit内部在验证第二个矩阵长度时发现ch语句。如果用户输入N或N，则不会返回主菜单选择。相反，它会继续代码并返回错误