Matrix Calculation by Java

package mypack;
import java.util.Scanner;

public class Matrix {
    private int row;
    private int col;
    private int[][] matrix;

    public Matrix(int trow, int tcol) {
        this.row = trow;
        this.col = tcol;
    }

    public Matrix(int trow, int tcol, int[][] m) {
        this.row = trow;
        this.col = tcol;
        this.matrix = m;
    }
   
public int[][] fill(){
        int[][] data = new int[row][col];
        Scanner input = new Scanner(System.in);

        for(int row = 0; row< matrix.length; row++){
            for(int col = 0 ;col< matrix[row].length; col++){
                System.out.println("enter the elements for the Matrix");
                data[row][col] = input.nextInt();
             }
            System.out.println();
        }
        return data;
    }

public void disp(int [][]m,String s)
{
     System.out.println(s + " matrix is : ");
     for (int i = 0; i <row ; i++) {
            for (int j = 0; j < col; j++) {
                  System.out.print(m[i][j] + " ");
            }
            System.out.println();
     }
}

public int[][] add(int [][]m1,int [][]m2){
    int [][]result=new int[row][col];
    for (int i = 0; i < row; i++) {
        for (int j = 0; j < col; j++) {
              result[i][j] = m1[i][j] + m2[i][j];
        }
 }
    return result;   
}

public int[][] sub(int [][]m1,int [][]m2){
    int [][]result=new int[row][col];
    for (int i = 0; i < row; i++) {
        for (int j = 0; j < col; j++) {
              result[i][j] = m1[i][j] - m2[i][j];
        }
 }
    return result;   
}

public int[][] multi(int [][]m1,int [][]m2){
    int [][]result=new int[row][col];
     for (int i = 0; i < row; i++) {
         for (int j = 0; j < col; j++) {
             for (int k = 0; k < col; k++) { //columns in matrix1= rows in matrix2
                 result[i][j] = result[i][j] + m1[i][k] * m2[k][j];
             }
         }
     }
    return result;   
}


public int[][] trans(int [][]m1){
    int [][]result=new int[row][col];
      for (int i = 0; i < row; i++) {
          for (int j = 0; j < col; j++)
                result[j][i] = m1[i][j];
   }

    return result;   
}

    public static void main(String[] args){
    
        Scanner input=new Scanner(System.in);
       
        System.out.println("Enter the First matrix Elements");
        int[][] ma1 = new int[2][2];
        Matrix q1 = new Matrix(2, 2,ma1);
        ma1=q1.fill();
        q1.disp(ma1,"first");
       
        System.out.println("Enter the Second matrix Elements");
        int[][] ma2 = new int[2][2];
        Matrix q2 = new Matrix(2, 2,ma2);
        ma2=q2.fill();
        q2.disp(ma2,"Second");
   
        char type;
        do{
             System.out.println("Choice any option");
             System.out.println("1.Addition");
             System.out.println("2.Substration");
             System.out.println("3.Mutlipication");
             System.out.println("4.Transpose");
             System.out.println("Choicee only integer type");
             System.out.println("Choice any option");
             int myinput=input.nextInt();
             switch(myinput){
             case 1:  int[][] ma3=new int[2][2];
                      Matrix q3=new Matrix(2,2,ma3);
                      ma3=q3.add(ma1,ma2);
                      q3.disp(ma3,"Addtion");
                      break;
           
             case 2:    int[][] ma4=new int[2][2];
                        Matrix q4=new Matrix(2,2,ma4);
                        ma4=q4.sub(ma1,ma2);
                        q4.disp(ma4,"Substration"); break;
                       
             case 3:  int[][] ma5=new int[2][2];
                      Matrix q5=new Matrix(2,2,ma5);
                      ma5=q5.multi(ma1,ma2);
                      q5.disp(ma5,"Multiplication"); break;
                     
             case 4:   System.out.println("Transpose for matrix press key :");
                       System.out.println("1.First matrix");
                       System.out.println("2.Second matrix");
                       int key=input.nextInt();
                       switch(key){
                       case 1: int[][] ma6=new int[2][2];
                               Matrix q6=new Matrix(2,2,ma6);
                               ma6=q6.trans(ma1);
                               q6.disp(ma6,"First Transpose"); break;
                       case 2: int[][] ma7=new int[2][2];
                                Matrix q7=new Matrix(2,2,ma7);
                                ma7=q7.trans(ma2);
                                q7.disp(ma7,"Second Transpose"); break;
                       default : System.out.println("enter wrong key value");
                              
                       } break;
           
             default : System.out.println("plzz enter correct input!!");        
             }
             System.out.println("Do u want Try Again");
             System.out.println("Just type Yes->y and No->any key");
             type = input.next().charAt(0);
           
            }while(type=='y'||type=='Y');
       
         System.out.println("BYE , Thanks for using...");
    }
 }