How to extract value from hash in Rails

Question

I have a Hash and need to use the value year from a variable in it The example is:

2.2.4 :001 > @values_project
=> [#<CustomValue id: 20367, customized_type: "Project", customized_id: 492, custom_field_id: 64, year: "2017">]

and I need the year so when I try @value_hash.year receive the error

NoMethodError: undefined method `year' for
#<ActiveRecord::Relation:0x0000000712fb18>

I don't understand why

Becki Srofe · Answer 1 · 2017-09-19T03:59:47.987

2

If you are trying to get the value for the key year and your hash is @values_project then you would use
@values_project[:year]

edited Sep 19 '17 at 03:59

answered Sep 19 '17 at 03:49

Becki Srofe

21
3

score 2 · Answer 2 · answered Sep 19 '17 at 03:50

2

since it is array of objects use like that

@values_project.each do |value_project|
  value_project.year
end

or

@values_project.first.year

answered Sep 19 '17 at 03:50

Sachin R

11,606
10
35
40

It's not *exactly* an 'array of objects'. It's an `ActiveRecord::Relation`. But, hey, I know what you're saying. – jvillian Sep 19 '17 at 04:06

score 1 · Accepted Answer · answered Sep 19 '17 at 04:05

@value_hash is not a hash, it's an ActiveRecord::Relation (as the error states).

In your example, @value_hash has only one member. To get that member, which is an instance of the class CustomValue (which is still not a hash!), you can do:

custom_value = @value_hash.first

Then, to get the year, you can do:

custom_value.year

Or, you could do it in one shot as:

@value_hash.first.year

Which is just a long way of saying exactly what Sachin R said (so you should accept their answer).

score 0 · Answer 4 · answered Jul 11 '19 at 14:11

0

You can try the following ways as well :

@value_project[0].year

answered Jul 11 '19 at 14:11

army_coding

154
6

How to extract value from hash in Rails

4 Answers4