How would I assign multiple instance variables the same value in the ruby initialize method? Looking to refactor the below:
def initialize
@weekly_stats = Hash.new {|h, k| h[k]={}}
@report_times = Hash.new {|h, k| h[k]={}}
@email_stats = Hash.new {|h, k| h[k]={}}
end
Not sure what doing this in a one-liner buys you but you could do something like this:
%w{weekly_stats report_times email_stats}.each { |v| instance_variable_set("@#{v}", Hash.new {|h, k| h[k]={}} }
Or break it into two non-duplicating lines like:
vars = %w{weekly_stats report_times email_stats}
vars.each { |v| instance_variable_set("@#{v}", Hash.new {|h, k| h[k]={}} }
Or combining it with jvnill's answer:
value = Hash.new {|h, k| h[k]={}}
vars = %w{weekly_stats report_times email_stats}
vars.each { |v| instance_variable_set("@#{v}", value.dup }
you can't do this in a single line because you're assigning a hash. Using Vinay's answer
>> a = b = c = { a: 'b', c: 'd' }
>> a # {:a=>"b", :c=>"d"}
>> a[:a] = 2 # 2
>> b # {:a=>2, :c=>"d"}
In the example above, b changed when you changed a. I'm not sure if there's a way to write this in a single line but try the following code instead
@weekly_stats = Hash.new {|h, k| h[k]={}}
@report_times = @weekly_stats.dup
@email_stats = @weekly_stats.dup
Try this,
@weekly_stats = @report_times = @email_stats = Hash.new {|h, k| h[k]={}}
This works, but you should know that it's only safe for your situation if you're using the variables for numbers, which are immutable in Ruby. If you tried the same thing with a string, for example, you could end up with some behavior you didn't expect:
ruby-1.9.2-p180 :001 > foo = bar = "string"
=> "string"
ruby-1.9.2-p180 :002 > foo.upcase!
=> "STRING"
ruby-1.9.2-p180 :003 > bar
=> "STRING"
