I have an Array that contains strings:
["First Name", "Last Name", "Location", "Description"]
I need to convert the Array to a Hash, as in the following:
{"A" => "First Name", "B" => "Last Name", "C" => "Location", "D" => "Description"}
Also, this way too:
{"First Name" => "A", "Last Name" => "B", "Location" => "C", "Description" => "D"}
Any thoughts how to handle this the best way?
You could implement as follows
def string_array_to_hash(a=[],keys=false)
headers = ("A".."Z").to_a
Hash[keys ? a.zip(headers.take(a.count)) : headers.take(a.count).zip(a)]
end
Then to get your initial output it would be
a = ["First Name", "Last Name", "Location", "Description"]
string_array_to_hash a
#=> {"A"=>"First Name", "B"=>"Last Name", "C"=>"Location", "D"=>"Description"}
And second output is
a = ["First Name", "Last Name", "Location", "Description"]
string_array_to_hash a, true
#=> {"First Name"=>"A", "Last Name"=>"B", "Location"=>"C", "Description"=>"D"}
Note: this will work as long as a is less than 27 Objects otherwise you will have to specify a different desired output. This is due to the fact that a) the alphabet only has 26 letters b) Hash objects can only have unique keys.
alphabet = ("A".."Z").to_a and then abstract a.zip(alphabet.take(a.count)) and alphabet.take(a.count).zip(a) to get your 2 desired results although I am not sure why you are opposed to a method.You could do this:
arr = ["First Name", "Last Name", "Location", "Description"]
letter = Enumerator.new do |y|
l = ('A'.ord-1).chr
loop do
y.yield l=l.next
end
end
#=> #<Enumerator: #<Enumerator::Generator:0x007f9a00878fd8>:each>
h = arr.each_with_object({}) { |s,h| h[letter.next] = s }
#=> {"A"=>"First Name", "B"=>"Last Name", "C"=>"Location", "D"=>"Description"}
h.invert
#=> {"First Name"=>"A", "Last Name"=>"B", "Location"=>"C", "Description"=>"D"}
or
letter = ('A'.ord-1).chr
#=> "@"
h = arr.each_with_object({}) { |s,h| h[letter = letter.next] = s }
#=> {"A"=>"First Name", "B"=>"Last Name", "C"=>"Location", "D"=>"Description"}
When using the enumerator letter, we have
27.times { puts letter.next }
#=> "A"
# "B"
# ...
# "Z"
# "AA"
Enumerable#next and inversion (of which I completely forgot about).Hash object. There are many methods for retrieval all are very easy.
'Z'.next => 'AA'. The Ruby monks are looking out for us.If you are not being specific about keys name then you could try this out
list = ["First Name", "Last Name", "Location", "Description"]
Hash[list.map.with_index{|*x|x}].invert
Output
{0=>"First Name", 1=>"Last Name", 2=>"Location", 3=>"Description"}
Similar solutions is here.
Or..You also can try this :)
letter = 'A'
arr = ["First Name", "Last Name", "Location", "Description"]
hash = {}
arr.each { |i|
hash[i] = letter
letter = letter.next
}
// => {"First Name"=>"A", "Last Name"=>"B", "Location"=>"C", "Description"=>"D"}
or
letter = 'A'
arr = ["First Name", "Last Name", "Location", "Description"]
hash = {}
arr.each { |i|
hash[letter] = i
letter = letter.next
}
// => {"A"=>"First Name", "B"=>"Last Name", "C"=>"Location", "D"=>"Description"}
