I have a hash where the keys are country_id's and I would like to change the country_id keys to actually have the name of the country. I have a function that can do the id to name conversion but I can't figure out how to get the keys updated and mapped correctly to their current values.
Also I'm not able to use transform_keys due to the version of ruby\rails I'm on.
I don't know what country will be selected so I need a way of looping through the keys and updating them, then storing back to the hash or a new hash with the values mapped correctly.
the hash I have is called #trending_countries the keys are currently the country_id that needs to be updated and the value consists of a count for that particular country.
#trending_countries = {22=>2, 34=>3} and I would like it in the format of #trending_countries = {United States=>2, Canada=>3}
I tried doing the below in my controller
#trending_countries.each {|k, v| #trending_countries[k] = Country.get_country_name(k)}
the function doing the id to name conversion is in a separate model called Country.
# returns the country name when a country id is given.
def self.get_country_name(country_id)
country = self.find_by(id: country_id)
return country.name
end
One way to do it is the following:
old_hash.map { |key, value| [Country.get_country_name(key), value] }.to_h
old_hash = { 62=>:wee, 12=>:big, 8=>:medium }
country_id_to_name = { 62=>"Monaco", 8=>"France", 12=>"China" }
old_hash.each_with_object({}) { |(k,v),h| h[country_id_to_name[k]] = v }
#=> {"Monaco"=>:wee, "China"=>:big, "France"=>:medium}
Related
I have an array of hashes as json, so how to check my array of hashes contains a hash with a given key-value pair.
This is my json
[{"question"=>"0a2a3452", "answer"=>"bull"}, {"question"=>"58deacf9", "answer"=>"bullafolo"}, {"question"=>"32c53e5f", "answer"=>"curosit"}, {"question"=>"b5546bcf", "answer"=>""}, {"question"=>"0f0b314", "answer"=>""}]
I tried looping through the json array, but this is tedious, as I need to check that if that json has that hash with a given key-value pair
It's a questionnaire form, in which I have to perform an update on answers
if !#client_find.nil?
#client_find.questionnaire
params[:commit].each do |key, value|
#json=[]
#json = #client_find.questionnaire
if !value.empty? && #json.include?(key)
puts "blunderc "+ value.inspect
#new_append = Hash.new
#new_append[:question] = key
#new_append[:answer]= value
#json << #new_append
end
if !key.empty? && !value.empty?
#logic
#json.each do |u|
if (u.key? key)
puts "bothu "+ u[key].inspect
u[key] = value
end
end
end
end
Array#any? iterates through the array. In each iteration I check wether the current hash has the searched question key or not. If a hash is found Array#any? returns true otherwise false.
array = [{"question"=>"0a2a3452", "answer"=>"bull"}, {"question"=>"58deacf9", "answer"=>"bullafolo"}, {"question"=>"32c53e5f", "answer"=>"curosit"}, {"question"=>"b5546bcf", "answer"=>""}, {"question"=>"0f0b314", "answer"=>""}]
search_for_key = '0a2a3452'
array.any?{|hash| hash['question'] == search_for_key}
I'll assume that you want to check the existence of a hash which has the key/value pair "quesetion" => "some-value".
Here's how you can do it:
array.any? { |item| item['question'] == 'some-question-id' }
Considering your are checking for a particular key exists or not
#json.any? {|obj| obj.key?(your_particular_key)
You can filter the array using Enumerable#select to get only the hashes that contains the desired key.
filtered = my_hash.select { |item| item['desired_key'] }
That's possible because nil is falsey. If you input is a raw JSON you'll need to parse it to a Ruby hash using JSON#parse or any other equivalent method.
filtered will give you all the hashes that contain the desired_key.
Is that what you want ?
Btw guitarman's answer is way better !
questions = [{"question"=>"0a2a3452", "answer"=>"bull"}, {"question"=>"58deacf9", "answer"=>"bullafolo"}, {"question"=>"32c53e5f", "answer"=>"curosit"}, {"question"=>"b5546bcf", "answer"=>""}, {"question"=>"0f0b314", "answer"=>""}]
result = questions.find { |question| question['question'] == "Bonour" }
if result.nil?
puts "Not found"
else
puts "#{result['question']} #{result['answer']}"
end
I am trying to search through an array of objects for a value, but am having trouble getting the find_index to work. In my code below, I am trying to search for the name (joseph) in the array. Is this the best way? I want to return that object after I search and find it.
name = "joseph"
array = [{"login":"joseph","id":4,"url":"localhost/joe","description":null},
{"login":"billy","id":10,"url":"localhost/billy","description":null}]
arrayItem = array.find_index {|item| item.login == name}
puts arrayItem
Your array contains a Hash, with keys that are symbols (in hashes, key: value is a shorthand for :key => value). Therefore, you need to replace item.login with item[:login]:
name = "joseph"
array = [{"login":"joseph","id":4,"url":"localhost/joe","description":nil},
{"login":"billy","id":10,"url":"localhost/billy","description":nil}]
arrayIndex = array.find_index{ |item| item[:login] == name }
puts arrayIndex
The code above retrieves the index at which the sought object is in the array. If you want the object and not the index, use find instead of find_index:
arrayItem = array.find{ |item| item[:login] == name }
Also, note that in Ruby, null is actually called nil.
I have a array which is inside a hash. I want know the result of the student (pass/fail) using the following array. First I have to match them with particular standard and compare their marks with the hash pass and fails. And I want to get the key pass or fail based on their mark. How to achieve this using Ruby?
array = [
{
:standard =>1
:pass=>{:tamil=>30,:eng=>25,:math=>35},
:fail=>{:tamil=>10,:eng=>15,:maths=>20}
},
{
:standard =>2,
:pass=>{:tamil=>40,:eng=>35,:math=>45},
:fail=>{:tamil=>20,:eng=>25,:maths=>30}
}
]
#student is assumed to be defined
standard = array.select {|standard| standard[:standard] == #student.standard}
eng_pass = #student.eng_mark >= standard[:pass][:eng]
eng_fail = #student.eng_mark <= standard[:fail][:eng]
return [eng_pass, eng_fail, whatever_else_you_want]
So on and forth for various topics.
The syntax in reading values from this structure is something like:
array[0][:pass][:eng]
and accordingly you can do the comparison as usual in batch:
for i in 0..#students_array.length
num = # student's score
standard = # something like array[0][:pass][:eng]
if num > standard
# something like 'put "You passed!"'
end
end
I'm using Rails and learning ActiveRecord and I came across a vexing problem. Here's an array in my model:
#sea_countries = ['Singapore','Malaysia','Indonesia', 'Vietnam', 'Philippines', 'Thailand']
And here's my ActiveRecord object:
#sea_funding = StartupFunding.joins(:startup)
.where('startups.locations LIKE ?', '%Singapore%')
What I'm trying to do is to return a result where a string in the 'locations' column matches any element in the Array. I'm able to match the strings to each element of an Array (as above), but I'm not sure how to iterate over the whole Array such that the element is included as long as there's one match.
The intent is that an element with multiple locations 'Singapore,Malaysia' would be included within #sea_funding as well.
Well, don't ask me why 'locations' is set as a string. It's just the way the previous developer did it.
You use an IN clause in your .where filter:
#sea_funding = StartupFunding.joins(:startup)
.where(["startups.locations IN (?)", #sea_countries])
#sea_countries.include?(startups.locations)
This will return a boolean TRUE if the value of the locations column in startups can be found in the sea_countries array, false if it is absent.
Could this work for you?
first = true
where_clause = nil
sea_countries.each do |country|
quoted_country = ActiveRecord::Base.connection.quote_string(country)
if first
where_clause = "startups.locations LIKE '%#{quoted_country}%' "
first = false
else
where_clause += "OR startups.locations LIKE '%#{quoted_country}%' "
end
end
#sea_funding = StartupFunding.joins(:startup)
.where(where_clause)
I need help with this...
I have a hash like this:
#ingredients = Hash.new
#ingredients[1] = "Biscottes Mini(recondo)"
#ingredients[2] = "Abadejo"
#ingredients[3] = "Acelga"
#ingredients[4] = "Agua de Coco"
#ingredients[5] = "Ajo"
#ingredients[6] = "Almidón de Arroz"
#ingredients[7] = "Anillos Con Avena Integral cheerios (nestle)"
#ingredients[8] = "Apio"
I need to search into that hash in order to find "Biscottes Mini(recondo)" when I write "scotte"
Some help?
Thk!
Why do you use a Hash here and not an Array? You do not seem to use other keys than integers.
Anyway, this solution works for both Array and Hashes:
search_term = 'scotte'
# you could also use find_all instead of select
search_results = #ingredients.select { |key, val| val.include?(search_term) }
puts search_results.inspect
See http://ruby-doc.org/core/classes/Enumerable.html#M001488
You can call select (or find if you only want the first match) on a hash and then pass in a block that evaluates whether to include the key/value in the result hash. The block passes the key and value as arguments, so you can evaluate whether either the key or value matches.
search_value = "scotte"
#ingredients.select { |key, value| value.include? search_value }