CODEWITHSUNDEEP
rubyarrayshash
Luigi
Luigi

Reputation: 5603

Clean way to search through hash keys in Ruby

I have a hash like so:

hash = {"jonathan" => "12", "bob" => 15 }

Then I have an array like so:

array = ['jon', 'bob']

I want to return the value of the key that includes a value in my array in the end.

The goal is something like this:

array.each do |name|
  if hash.key.include? name
  return hash.value
end

What's the best way to write that code block?

Upvotes: 1

Views: 154

Answers (4)

Arup Rakshit
Arup Rakshit

Reputation: 118271

Here is how I would write :

hash = {"jonathan" => "12", "bob" => 15 }
array = ['jon', 'bob']
array.collect(&hash.method(:[])).compact # => [15]

Upvotes: 0

Малъ Скрылевъ
Малъ Скрылевъ

Reputation: 16507

Also you can use select methods of Hash:

hash.select {| k,_ | array.include?( k ) }
# => {"bob"=>15}

and get, for example, last value:

hash.select {| k,_ | array.include?( k ) }.to_a.flatten.last
# => 15

or even use values_at method of Hash:

hash.values_at( *array ).compact.last
# => 15

Upvotes: 1

falsetru
falsetru

Reputation: 369054

If you want multiple values, use Hash#values_at:

hash = {"jonathan" => "12", "bob" => 15 }
array = ['jon', 'bob']
hash.values_at(*array.select{|key| hash.has_key? key})
# => [15]

Using Array#&:

hash.values_at(*(hash.keys & array))
# => [15]

Upvotes: 1

zwippie
zwippie

Reputation: 15515

To get the keys, you don't need a block, this will do:

hash.keys & array

This takes the keys of the hash and intersect it with the array.

Second part, get a value from the hash:

hash[(hash.keys & array).last]

This will get the last key that is shared in hash and array and returns the value of that key in hash.

Upvotes: 1

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