Question

I’m passing the below information through parameter from view to controller

parameters:{"Something"=>{"a" => "1", "b" => "0", "c" => "1", "d" => "0" #and so on}}

I want to access all the characters that have “1” as their value and concatenate into the string.

I tried

Something.each do |key, value|
if(value == "1")
string = string + key
end 
end

It is throwing error saying that it could not execute nil.each and that i might be expecting an array.
It appears to me that Something is a hash and in turn has some hashes in it.
So i initialised Something to

Something = Hash.new { |Something, k| Something[k] = Hash.new }

But i still get the same error.

Answer 1

Just work with the params hash. This should do what you need:

params["Something"].select {|k, v| v == "1"}.keys.reduce(:+)

• select filters the params to only those with the value "1"
• keys returns an array with all the keys in the hash
• reduce joins all elements with a concat operation (+)

Edit

To concatenate and add the “Extra” word:

• For each parameter:

  params["Something"].select {|k, v| v == "1"}.keys.inject("") {|result, p| result += "Extra #{p}"}
  

• Only to the extra parameters, but not to the first one:

  params["Something"].select {|k, v| v == "1"}.keys.inject {|result, p| result += "Extra #{p}"}
  

See more information on inject here.