CODEWITHSUNDEEP
arraysrubyruby-on-rails-3
mamesaye
mamesaye

Reputation: 2153

Ruby remove empty, nil arrays strings from array of strings

I have this array of arrays: 

["[]", "[\"https://somewebsite1.com\"]", "[\"https://somewebsite2.com\"]", "[]", "[]", "[]", "---\n- https://somewebsite3.com\n", "--- []\n", "---\n- https://somewebsite4.com\n", "--- []\n", "--- []\n", "---\n- https://somewebsite.com\n", "---\n- https://somewebsite5.com\n", nil, nil, nil, nil, nil]

How can I:
1- remove all the empty, nil element
2- have an array of string: 

["https://somewebsite1.com", "https://somewebsite2.com", "https://somewebsite3.com", "https://somewebsite4.com", "https://somewebsite.com", "https://somewebsite5.com"]

array.select &:present? remove nil
then array.delete_if {|i| i == '[]'} remove []
so I am left with : 

["[\"https://somewebsite1.com\"]", "[\"https://somewebsite2.com\"]",  "---\n- https://somewebsite3.com\n", "--- []\n", "---\n- https://somewebsite4.com\n", "--- []\n", "--- []\n", "---\n- https://somewebsite.com\n", "---\n- https://somewebsite5.com\n"]

Upvotes: 0

Views: 4894

Answers (2)

Mark Tabler
Mark Tabler

Reputation: 1429

To just remove nil elements, you can use the compact method on an array. To remove both nil and empty strings, you can use the select method:

my_array.select! { |element| element&.size.to_i > 0 }

To process the remaining strings, you'll need to iterate over each string and figure out whether it needs YAML parsing or not. The method you'll use to collect the results of that iteration is map:

my_array.map! { |element| clever_string_parsing_on(element) }

Upvotes: 1

Stanislav Mekhonoshin
Stanislav Mekhonoshin

Reputation: 4386

First of all, it is a simple array of strings.

You can remove nil elements using array.compact or array.reject(&:nil?)

And to remove empty yaml entries you can use deserialization

array.compact .reject { |i| YAML.parse(i).children.first.children.empty? } .map { |i| i.gsub('["', '').gsub('"]', '').gsub("---\n- ", '').strip }

So the output would be you stated.

Update:

Another approach, without string manipulation

res = a.compact
deserialized = res.map { |i| YAML.parse(i) }
res = deserialized.reject { |i| i.children.first.children.empty? }
res.map { |i| i.children.first.children.first.value }

Upvotes: 3

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