I have a issue.. Appending - ruby

Question

I have this code:
1 #!/local/usr/bin/ruby
2
3 users = (1..255).to_a
4
5 x = " "
6 y = " "
7 z = " "
8 #a = " "
9
10 count = 1
11 users.each do |i|
12 x << i if count == 1
13 y << i if count == 2
14 z << i if count == 3
15 # if x.length == 60
16 # a << i if count == 1
17 # a << i if count == 2
18 # a << i if count == 3
19 # else
20 # end
21 if count == 3
22 count = 1
23 else
24 count += 1
25 end
26 end
27
28 puts x.length
29 puts y.length
30 puts z.length
31 #puts a.length
32
What this code does is append The numbers 1-255 into three different strings and outputs how many numbers are in each string.
IT WORKS
Example of working code:
[user#server ruby]$ ruby loadtest.rb
86
86
86
[user#server ruby]$
Now what I want it to do is have a failsafe called a as seen above, commented out, What I want is this, if each string contains 60 numbers I want it to append into the a string until there are no more numbers.
When I try to do it with the commented out section it outputs this:
[user#server ruby]$ ruby loadtest.rb
86
86
86
4
[user#server ruby]$ ruby loadtest.rb
WHY?! What am I doing wrong?

Answer 1

What this code does is append The numbers 1-255 into three different strings and outputs how many numbers are in each string.
After reducing the number of values being iterated for readability, here's what it's doing:
users = (1..5).to_a
x = " "
y = " "
z = " "
count = 1
users.each do |i|
x << i if count == 1 # => " \u0001", nil, nil, " \u0001\u0004", nil
y << i if count == 2 # => nil, " \u0002", nil, nil, " \u0002\u0005"
z << i if count == 3 # => nil, nil, " \u0003", nil, nil
if count == 3
count = 1
else
count += 1
end
end
x # => " \u0001\u0004"
y # => " \u0002\u0005"
z # => " \u0003"
puts x.length
puts y.length
puts z.length
# >> 3
# >> 3
# >> 2
Your code is creating binary inside the strings, not "numbers" as we normally think of them, as digits.
Moving on, you can clean up your logic using each_with_index and case/when. To make the results more readable I switched from accumulating into strings into arrays:
users = (1..5).to_a
x = []
y = []
z = []
users.each_with_index do |i, count|
case count % 3
when 0
x << i
when 1
y << i
when 2
z << i
end
end
x # => [1, 4]
y # => [2, 5]
z # => [3]
puts x.length
puts y.length
puts z.length
# >> 2
# >> 2
# >> 1
The real trick in this is the use of %, which does a modulo on the value.

Answer 2

... if each string contains 60 numbers I want it to append into the a string until there are no more numbers
As written, you are unconditionally appending to x,y,z even after they hit your limit.
You need to add a conditional around this code:
x << i if count == 1
y << i if count == 2
z << i if count == 3
so that it stops appending once it hits your limit.
By the looks of the else block that does nothing, I think you were headed in that direction:
if x.length == 60
a << i if count == 1
a << i if count == 2
a << i if count == 3
else
x << i if count == 1
y << i if count == 2
z << i if count == 3
end
Even that, though, won't do exactly what you want.
You'll want to check the string you are appending to to see if it has hit your limit yet.
I'd suggest refactoring to make it cleaner:
users.each do |i|
target_string = case count
when 1 then x
when 2 then y
when 3 then z
end
target_string = a if target_string.length == 60
target_string << i
if count == 3
count = 1
else
count += 1
end
end

Answer 3

It may be better to use an array instead of string as you are pushing numbers into those variables.
Let me propose a solution which achieves more or less what you are trying to do, but uses few Ruby tricks that may be useful in future.
x, y, z = r = Array.new(3) {[]}
a = []
iter = [0,1,2].cycle
(1..255).each do |i|
r.all? {|i| i.size == 60} ? a << i : r[iter.next] << i
end
p x.size, y.size, z.size
p a.size
Let's define our arrays. Even though I have arrays x, y, and z, they are there only because they were present in your code - I think we just need three arrays, each of which would collect numbers as they are picked from a range of numbers - between 1 to 255 - one by one. x,y,z = r uses parallel assignment technique and is equivalent to x,y,z = r[0],r[1],r[2]. Also, use of Array.new(3) {[]} helps in creating the Array of Array such that when we access r[1] it is initialized with empty array([]) by default.
x, y, z = r = Array.new(3) {[]}
a = []
In order to determine which array the next number picked from range has to be placed in, we will use an Enumerator generated from Enumerable#cycle. This enumerator is special - because it is soft of infinite in nature - and we can keep asking it to give an element by calling next, and it will cycle through the array elements of [0,1,2] - returning us 0,1,2,0,1,2,0,1,2... infinitely.
iter = [0,1,2].cycle
Next, we will iterate through the range of numbers 1..255. During each iteration, we will check whether all the 3 arrays in which we are collecting number have desired size of 60 with the help of Enumerable#all? - if so, we will append the number to array a - else we will assign it to one of the sub arrays of r based on the array index returned by iter enumerator.
(1..255).each do |i|
r.all? {|i| i.size == 60} ? a << i : r[iter.next] << i
end
Finally, we print the size of each of the array.
p x.size, y.size, z.size
#=> 60, 60, 60
p a.size
#=> 75