Print out 2D array - ruby

Question

array = Array.new(10) { Array.new(10 , 0)}
array.each { |x| print x }
Prints out one single line of ten [0, 0, 0, 0, 0, 0, 0, 0, 0, 0].
If I were to change print to puts, I then get 100 0 down the page.
How do I print out each array on a separate line without the "[]" and ","?
Something like:
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0

Answer 1

Suppose:
arr = Array.new(10) { (0..20).to_a.sample(10) }
Then
puts arr.map { |x| x.join(' ') }
1 9 6 15 7 19 18 3 0 12
13 20 18 15 0 3 19 1 14 16
7 16 5 3 12 19 4 9 20 10
6 10 9 1 18 17 7 19 5 15
12 3 8 16 10 5 2 18 20 6
12 9 0 18 2 11 16 8 7 15
8 9 14 19 3 16 6 20 13 17
7 19 16 14 13 6 9 2 3 5
10 17 8 15 11 2 13 14 16 7
14 9 20 17 15 3 4 2 11 19
is not very, er, attractive. For something more pleasing, you could quite easily do something like this:
width = arr.flatten.max.to_s.size+2
#=> 4
puts arr.map { |a| a.map { |i| i.to_s.rjust(width) }.join }
1 9 6 15 7 19 18 3 0 12
13 20 18 15 0 3 19 1 14 16
7 16 5 3 12 19 4 9 20 10
6 10 9 1 18 17 7 19 5 15
12 3 8 16 10 5 2 18 20 6
12 9 0 18 2 11 16 8 7 15
8 9 14 19 3 16 6 20 13 17
7 19 16 14 13 6 9 2 3 5
10 17 8 15 11 2 13 14 16 7
14 9 20 17 15 3 4 2 11 19
If you have too many columns to display on the screen you can do this:
puts arr.map { |a| a.map { |i| i.to_s.rjust(width) }.join.tinyfy }
1 9 6 15 7 19 18 3 0 12
13 20 18 15 0 3 19 1 14 16
7 16 5 3 12 19 4 9 20 10
6 10 9 1 18 17 7 19 5 15
12 3 8 16 10 5 2 18 20 6
12 9 0 18 2 11 16 8 7 15
8 9 14 19 3 16 6 20 13 17
7 19 16 14 13 6 9 2 3 5
10 17 8 15 11 2 13 14 16 7
14 9 20 17 15 3 4 2 11 19

Answer 2

Try join:
array.each { |x|
puts x.join(" ")
}
# prints:
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0

Answer 3

Print a 2-dimensional array with spacing between columns
Accepts a 2d array of objects that have a to_s method (strings integers floats and booleans..) and an optional margin width integer.
Update: It now works with arrays of varying lengths.
def print_table(table, margin_width = 2)
# the margin_width is the spaces between columns (use at least 1)
column_widths = []
table.each do |row|
row.each.with_index do |cell, column_num|
column_widths[column_num] = [column_widths[column_num] || 0, cell.to_s.size].max
end
end
puts (table.collect do |row|
row.collect.with_index do |cell, column_num|
cell.to_s.ljust(column_widths[column_num] + margin_width)
end.join
end)
end
Note: the parenthesis after the puts statement is required so table.collect and the do end block are not passed as two separate parameters to the puts method.
Example table
my_table = [
["1", "Animal", "Dog", "1"],
[1, "Animal", "Cat", "2"],
[1, "Animal", "Bird", "3"],
[2, "Place", "USA", "1"],
[2.5, "Place", "Other", "2"],
[3, "Color", "Red"],
[3, "Color", "Blue", "b"],
[3, "Some more color", "Orange", "c"],
[4.7, "Age", "Young", "a"],
[4, "Age", "Middle", "b"],
[4, "Age", "Old", "c"],
[5, "Alive"],
[],
[5, "Alive", false, "n"]
]
print_table my_table
Prints:
1 Animal Dog 1
1 Animal Cat 2
1 Animal Bird 3
2 Place USA 1
2.5 Place Other 2
3 Color Red
3 Color Blue b
3 Some more color Orange c
4.7 Age Young a
4 Age Middle b
4 Age Old c
5 Alive
5 Alive false n
(Not colored. The coloring above was added by StackOverflow.)

Answer 4

You may want to write your own method to do it. Something like:
def array_2D_print array
array.each do |arr|
arr.each do |item|
print "#{item} "
end
print "\n"
end
end
If you only use this once in your code, you might also consider not creating any method:
array.each do |arr|
arr.each do |item|
print "#{item} "
end
print "\n"
end
This solution has the advantage of being easier to modify than other alternatives, to match what you want to print.