Agfdhyk

I am not understanding a particular part of the following assignment and why my loops with a 2D matrix of this assignment is not generating the proper output.

I am getting too many rows and columns in the output. I also need help with the formatting of the output to make it readable.

The assignment is to do the following:

public void getMultiplicationTable()

This method will use a while loop to ask the user to enter two integer numbers between 1 and 10. The while loop will stop if the numbers provided by the user were in the specified range; otherwise, an error message will be printed and the user will be asked to enter another two numbers.

The first number given by the user will be incremented by one then used as the rows number and the second one will be incremented by 1 and used as the column number of a two-dimensional array. The method will calculate the multiplication table and store it in the array and then display it.

For example, if the user entered 5 & 7 your code should create an int array with 6 rows and 8 columns and then creates and load the array with the multiplication table. The printed result should be like so:

0  0  0  0  0  0  0  0

0  1  2  3  4  5  6  7

0  2  4  6  8 10 12 14

0  3  6  9 12 15 18 21

0  4  8 12 16 20 24 28

0  5 10 15 20 25 30 35

Where I am getting stuck is the part where it says:

The first number given by the user will be incremented by one then used as the rows number and the second one will be incremented by 1 and used as the column number of a two-dimensional array. The method will calculate the multiplication table and store it in the array and then display it.

I cannot seem to get the numbers that I have inputted to be used as the row and column length, and the print out will print multiples of up to ten (although I guess technically nine, since I have not used + 1). Any help that can be provided would be greatly appreciated. Here is what I have so far:

public void getMultiplicationTable(){



    Scanner numsEnter = new Scanner(System.in);



    int table = new int[10][10];



    int numRow = 0;

    int numCol = 0;



    System.out.println("Please enter in two numbers: ");



    while(true){

        numRow = numsEnter.nextInt();

        numCol = numsEnter.nextInt();

        if((numRow >= 1 && numRow <= 10) && (numCol >= 1 && numCol <= 10)){

            break;

        }else{

            System.out.println("These numbers are invalid, please enter two numbers between 0 & 10");

        }

    }



    numRow++;

    numCol++;



    for(int row=0; row < table.length; row++){

        for(int column = 0; column < table[row].length; column++){

            System.out.print(table [row] [column] = (row) * (column) );

        }

        System.out.println();

    }

}

Here is the output that I am getting with this, using 5 & 7 as the numbers inputted:

Please enter in two numbers: 

5

7



0000000000

0123456789 

024681012141618

0369121518212427

04812162024283236

051015202530354045

061218243036424854

071421283542495663

081624324048566472

091827364554637281

Thank you!

You can set your array size to match your user inputs if you just ask for them first, and define your 2D array after that. You're currently hard coding your 2D array to be a 10x10, but your logic is correct other than that.

Here is what it should look like.

    public void getMultiplicationTable(){



      Scanner numsEnter = new Scanner(System.in);



    System.out.println("Please enter in two numbers: ");



    int numRow = numsEnter.nextInt();

    int numCol = numsEnter.nextInt();



    int table = new int[numRow+1][numCol+1];



    System.out.println("Please enter in two numbers: ");



    while(true){

        if((numRow >= 1 && numRow <= 10) && (numCol >= 1 && numCol <= 10)){

            break;

        }else{

            System.out.println("These numbers are invalid, please enter two numbers between 0 & 10");

            numRow = numsEnter.nextInt();

            numCol = numsEnter.nextInt();

        }

    }



    numRow++;

    numCol++;



    for(int row=0; row < table.length; row++){

        for(int column = 0; column < table[row].length; column++){

            System.out.print(table [row] [column] = (row) * (column) );

            System.out.print(" ");

        }

        System.out.println();

    }



    }

The code above will output the following for an input of 5 7:

0 0 0 0 0 0 0 0 

0 1 2 3 4 5 6 7 

0 2 4 6 8 10 12 14 

0 3 6 9 12 15 18 21 

0 4 8 12 16 20 24 28 

0 5 10 15 20 25 30 35 

It’s because you declare the table to be a 10x10 array to start then use the length of the array in your condition in the for loops. You should create the table after you know the size of the table (or change your conditions).