I have an array as
["first_name"]
and I want to convert it to
["user.first_name"]
I cannot figure out how I can do this in rails.
2 Answers
If you would like to append text to the values you have in a array you're going to probably want to loop through the data and append to each element in the array like so:
my_array = ["test", "test2", "first_name"]
new_array = my_array.collect{|value| "user.#{value}" }
new_array will now be:
["user.test", "user.test2", "user.first_name"]
You could also just overwrite your original array by using collect! like so
my_array = ["test", "test2", "first_name"]
my_array.collect!{|value| "user.#{value}" }
This will of course overwrite your original original data in my_array
If you would like to just change one value in the array you could use the index of that array and assign the value
my_array = ["test", "test2", "first_name"]
my_array[1] = "user.#{my_array[1]}}
my_array will now read:
["test", "user.test2", "first_name"]
Ruby doc info: https://ruby-doc.org/3.2.2/Array.html#method-i-collect
collect and map are alias for each other fyi.
Comments
Supposing you've multiple elements in your array, I recommend using .map.
It allows you to iterate the array elements, and return a new value for each of them.
%w[first_name last_name email].map do |attr|
"user.#{attr}"
end
# => [user.first_name, user.last_name, user.email]
arr[0] = "user.#{arr[0]}"orarr[0].prepend('user.')orarr[0].insert(0,'user.')or ...?arr = ["first_name"]; arr[0].prepend('user.'); arr #=> ["user.first_name"]<- updates the string inside the array. You you have to do this a bunch of times thenarr.map(&'user.'.method(:+))would work too and will return a new array