Rails remove subarray from array

Question

In my Rails 5 app I have something like this:

a = [1,2,3]

a.map do |entry|
  entry.delete if condition == true
end

This removes the entry if the condition is true.

Now I have this:

a = [[1,2],[2,3],[3,4]]

a.map do |entry|
  entry.delete if condition == true
end

This loops through a but now entry is an array and delete should remove the entire entry but instead I get:

wrong number of arguments (given 0, expected 1)

Dos anybody know how I can loop through an array of arrays and remove an entire subarray?

Cody Caughlan · Accepted Answer · 2019-05-28 00:21:16Z

5

Try this: a.delete_if {condition}

For example:

a = [[1,2],[2,3],[3,4]]
a.delete_if {|entry| entry[0] == 1 } 
# returns [[2, 3], [3, 4]]

Cody Caughlan

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answered May 28, 2019 at 0:10

Muhammad Umair

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Comments

Vishal · Accepted Answer · 2019-05-28 07:45:43Z

0

instead of using map you should use flat_map see: https://apidock.com/ruby/Enumerable/flat_map

answered May 28, 2019 at 7:45

Vishal

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