Question

How to build this sequence in ruby?

{
"0" => "00000",
"1" => "00001",
"2" => "00002",
"3" => "00003",
"4" => "00010",
"5" => "00011",
"6" => "00012",
....
"1020" => "33330",
"1021" => "33331",
"1022" => "33332",
"1023" => "33333"
}

Answer 1

You can do:

nums = Hash.new
0.upto(1023){ |x| nums[x] = x.to_s(4) }
puts nums

Basically Fixnum.to_s(4) will convert your base 10 number to base 4.

Update – As a one liner

If you want a one liner, you can do:

puts (0..1023).inject({}){ |hash, e| hash[e] = e.to_s(4); hash }