Question

I am very new to Ruby, and programming in general. Firstly, I have the below code:

hashy = {"a" => 1, "b" => 2, "c" => 3, "d" => 4, "e" => 6, "f" => 6}
array = ["a", "b", "c"]
string = "df"
array.push (string.split(//))
puts array
test = array.map {|a| hashy.select {|k,v| a == k}}

puts test

This code successfully maps ‘a’, ‘b’ and ‘c’ to the hash, and populates test with the keys and values from the hash.

This always works for a pre-defined array. However if I add to the array from a string (in this case the string “df”, or create an array from a string, it no longer maps the array values to the hash, and I can’t see why. I’ve looked at different ways of populating the array with the string values, but each time get the same problem.

As far as I can see “df” should also be mapping to the hash.

Any help would be greatly appreciated.

Answer 1

It’s because you pushing string.split(//) array to array as one object, so you have one array element among the numbers in array as result.

array = ["a", "b", "c"]
string = "df"
array.push (string.split(//))
 => ["a", "b", "c", ["d", "f"]]

To avoid this, you can use array concatenation, for example

array = ["a", "b", "c"]
string = "df"
array += string.split(//)
=> ["a", "b", "c", "d", "f"]