Element Replace - Ruby

Question

I am trying to create a new array where elements of the original array are replaced with their corresponding values in the hash. I want to compare every element in arr to the key in hash and if they are equal shovel them into the arr and return it at the end. Why is my code not working and how can I access/return the key value of the respective entry in hash, not only the value pointed to by the key? If you get what I am saying.

def element_replace(arr, hash)
  count = []
    
  
  for i in arr do
    if i == hash.key
     count << value
    else 
      count << i 
    end
  end
   
  return count

end

arr1 = ["LeBron James", "Lionel Messi", "Serena Williams"]
hash1 = {"Serena Williams"=>"tennis", "LeBron James"=>"basketball"}
print element_replace(arr1, hash1) # => ["basketball", "Lionel Messi", "tennis"]
puts

arr2 = ["dog", "cat", "mouse"]
hash2 = {"dog"=>"bork", "cat"=>"meow", "duck"=>"quack"}
print element_replace(arr2, hash2) # => ["bork", "meow", "mouse"]
puts

Answer 1

Ruby's Hash::fetch would be a technique to get your desired result:

> players = ["LeBron James", "Lionel Messi", "Serena Williams"]
=> ["LeBron James", "Lionel Messi", "Serena Williams"]
> sports_data = {"Serena Williams"=>"tennis", "LeBron James"=>"basketball"}
=> {"Serena Williams"=>"tennis", "LeBron James"=>"basketball"}
> players.map { |player| sports_data.fetch(player, player) }
=> ["basketball", "Lionel Messi", "tennis"]