# Ruby program to print the right diagonal matrix

Ruby Example: Write a program to print the right diagonal matrix.
Submitted by Nidhi, on January 25, 2022

Problem Solution:

In this program, we will create a matrix using the 2D array. Then we read elements of the matrix from the user. After that, we will print the right diagonal matrix.

Program/Source Code:

The source code to print the right diagonal matrix is given below. The given program is compiled and executed successfully.

```# Ruby program to print the
# right diagonal matrix

TwoDArr = Array.new(3){Array.new(3)}

printf "Enter elements of MATRIX:\n";
i = 0;
while (i < 3)
j = 0;
while (j < 3)
printf "ELEMENT [%d][%d]: ", i, j;
TwoDArr[i][j] =  gets.chomp.to_i;
j = j + 1;
end
i = i + 1;
end

printf "MATRIX:\n";
i = 0;
while (i < 3)
j = 0;
while (j < 3)
print TwoDArr[i][j]," ";
j = j + 1;
end
i = i + 1;
print "\n";
end

printf("Right diagonal of matrix:\n")
i = 0;
while (i < 3)
j = 0;
while (j < 3)
if ((i + j) == 2)
printf "%d ", TwoDArr[i][j];
else
printf(" ");
end
j = j + 1;
end
i = i + 1;
print "\n";
end
```

Output:

```Enter elements of MATRIX:
ELEMENT [0][0]: 1
ELEMENT [0][1]: 2
ELEMENT [0][2]: 3
ELEMENT [1][0]: 4
ELEMENT [1][1]: 5
ELEMENT [1][2]: 6
ELEMENT [2][0]: 7
ELEMENT [2][1]: 8
ELEMENT [2][2]: 9
MATRIX:
1 2 3
4 5 6
7 8 9
Right diagonal of matrix:
3
5
7
```

Explanation:

In the above program, we created a 3X3 matrix TwoDArr using the 2D array. Then we read the elements of the matrix. After that, we printed the right diagonal of the matrix.