I have an array
@a = ["a","b","c","d"]
and this is my hash
@a_hash ={"b"=> ["1","2","3"]}
now I want to replace the value of the "b" with @a_hash value into the array.
my expected result is
@a = ["a",["1","2","3"],"c","d"]
How can i get this in ruby?
Perhaps like this:
a = ["a","b","c","d"]
a_hash ={"b"=> ["1","2","3"]}
a.map! { |x| a_hash[x] || a }
a #=> ["a",["1","2","3"],"c","d"]
You can use #fetch method
@a = ["a","b","c","d"]
#=> ["a", "b", "c", "d"]
@a_hash ={"b"=> ["1","2","3"]}
#=> {"b"=>["1", "2", "3"]}
@a.map! { |e| @a_hash.fetch(e, e) }
#=> ["a", ["1", "2", "3"], "c", "d"]
Use Array#index:
@a[@a.index("b")] = @a_hash["b"]
@a
#=> ["a", ["1", "2", "3"], "c", "d"]
It's probably the fastest solution if you have only one occurrence of 'b'. For each occurrence of "b":
@a.map! {|e| @a_hash["b"] if e == "b"}
@a does not have an element "b". I do like the use of index, however, as it terminates as soon as it finds a match (if there is one), unlike the selected answer, which enumerates all elements of @a. Just add a step: i = @a.index("b"); @a[i] = @a_hash["b"] if a (which returns nil if i.nil? #=> true).You can just assign the element to be the value of the hash key:
@a[1] = @a_hash['b']
That's it.
@a = ["a", ["1", "2", "3"], "c", "d"]. :-)
@ais known to contain exactly one element"b"and if not, what is to be done. You can provide an example to clarify your intent but it is not a substitute for a complete and unambiguous statement of the question.