Ruby: eliminate strings that are substrings of other strings in an array

Question

I thought this would be an interesting question to post. I have a solution, I'm curious if there is a better way to do this. Say you have this array:

names = ["on", "question", "quest"]

I want to eliminate strings that are substrings of other members in the array. The cleanest code I could come up with is:

names.select do |name|
    names.all? { |other_name| other_name == name || other_name.match(name).nil? }
end

The result is

["question"]

I hate that code, just doesn't seem very ruby like. Any suggestions on a better / more efficient / more concise way to do this?

Thanks for the help.

Is the other_name == name || necessary? Would be a bit cleaner without it. — Jeff Swensen
– Jeff Swensen, Commented Mar 4, 2011 at 3:40
Yes, otherwise everything would be excluded, including "question". — Binary Logic
– Binary Logic, Commented Mar 4, 2011 at 17:37

rubyprince · Accepted Answer · 2011-03-04 06:13:16Z

2

I have a little addition to make. Use include? method of string

names.select do |name|
  names.one? {|other_name| other_name.include? name}
end

answered Mar 4, 2011 at 6:13

rubyprince

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Comments

RameshVel · Accepted Answer · 2011-03-04 04:42:14Z

1

Wouldn't this easier

names.select do |name|
      names.one? {|other_name|  other_name.index(name)!=nil}
end

It checks if the item is a part of any one of the item in array.

answered Mar 4, 2011 at 4:42

RameshVel

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Yep, that is better. Appreciate the help.

That can be shortened even more using names.one? { |other_name| other_name[name] }