Question

Consider the following definitions

int[ ][ ] numbers = {{1, 2, 3},

                                {4, 5, 6} };

The following code below produces

for (int row = numbers.length - 1; row >= 0; row -- )

{

for (int col = 0; col < numbers[0].length; col ++)

{

System.out.print (numbers [row][col]);

}

}

Answer 1

The code produces the following output:

456123

Explanation:

//Here is a 2D array with 2 rows and 3 columns

int[ ][ ] numbers = {{1, 2, 3}, {4, 5, 6} };

//the for loop below starts from values row= 2-1 = 1

// so the loop runs from 1 to 0

for (int row = numbers.length - 1; row >= 0; row -- )

{

// this loop is for each columns runs from 0 to less than 3

// here we are accessing 0th, 1st and 2nd columns of each row

for (int col = 0; col < numbers[0].length; col ++)

{

// printing the current index value of 2d matrix numbers

System.out.print(numbers [row][col]);

}

}

so , if you see we counting rows 1 to 0

and columns from 0 to 2

1st row 0th,1st and 2nd column values gets printed followed by 0th row 1st and 2nd column values gets printed.

456123