nested loops

nested_loops.rb

num_columns = 7
num_rows = 4
col_sums = Array.new(num_columns, 0)
(0...num_rows).each do |col|
  row_sum = 0
  (0...num_columns).each do |row|
    val = row*col
    print "#{val}\t"
    row_sum += val
    col_sums[row] += val
  end
  puts "*#{row_sum}\t"
end
col_sums.each {|sum| print "#{sum}\t" }
puts

NestedLoop.java

public class NestedForLoop {
	public static void main(String[] args) {
		int numRows = 4;
		int numColumns = 7;
		int[] columnSums = new int[numColumns];
		for (int row = 0; row < numRows; row++) {
			int rowSum = 0;
			for (int column=0; column < numColumns; column++) {
				int value = row * column;
				System.out.print(value + "\t");
				rowSum += value;
				columnSums[column] += value;
			}
			System.out.println("*" + rowSum);
		}

		for (int columnSum : columnSums ) {
			System.out.print(columnSum + "\t");
		}
		System.out.println();
	}
}