Ruby – Identify and Update Duplicates in Array with Index Value

May 12, 2023

I have an array which may or may not include duplicates, but no nil or "" values.

array = ["Ballerina", "Lagoon", "Black", "Space", "Golden", "Lagoon"]

This is really the closest I’ve gotten to solving the problem, but the problem here is that I don’t know the duplicates, so its not really valid:

array.each_with_index.map {|value, index| array[index] == "Lagoon" ? index : ""}.uniq

What I’m looking to return is for any duplicates in the array to concatenate the index value onto the end of the array value. So the end result would be:

array = ["Ballerina", "Lagoon 1", "Black", "Space", "Golden", "Lagoon 5"]

Thanks

>Solution :

One way is to use the Array count method inside your map loop.

array = ["Ballerina", "Lagoon", "Black", "Space", "Golden", "Lagoon"]


new_array = array.each_with_index.map do |value, index| 
    value_duplicated = array.count(value) > 1
    if value_duplicated 
        "#{value} #{index}"
    else
       value 
    end
end

puts new_array