trying to iterate 3d array | undefined method `each' for nil:NilClass - ruby-on-rails

Question

what i'm making wrong?
The first 7 lines from the Array i can iterate but when i'm trying to open the another dimension than i receive an error.
My Code
require 'rest-client'
class ApiController < ApplicationController
def listings
url = 'https://api.coinmarketcap.com/v2/ticker/'
response = RestClient.get(url)
#jsonData = JSON.parse(response)
end
end
api_controller works
<h1>LISTING </h1>
<% #jsonData["data"].each do |coin| %>
<%coin.each do |id| %>
Name: <%= id["name"] %> <br />
Symbol: <% id["symbol"] %><br />
Website_slug: <% id["website_slug"] %><br />
Rank: <% id["rank"] %><br />
Circulating_supply: <% id["circulating_supply"] %><br />
total_supply: <% id["total_supply"] %><br />
max_supply: <% id["max_supply"] %><br />
till here it works
begin here it not works
<%id["quotes"].each do |quotes| %>
<%quotes.each do |usd| %>
Price: <% usd["price"] %><br />
Volume24h: <%= usd["volume_24h"] %><br />
Market_cap: <%= usd["market_cap"] %><br />
Change_1he: <%= usd["pricpercent_change_1he"] %><br />
Change_24h: <%= usd["percent_change_24h"] %><br />
Change_7d: <%= usd["percent_change_7d"] %><br />
<%end%>
<%end%>
<%end%>
<%end%>
{"1"=>{"id"=>1, "name"=>"Bitcoin", "symbol"=>"BTC", "website_slug"=>"bitcoin", "rank"=>1, "circulating_supply"=>17298850.0, "total_supply"=>17298850.0, "max_supply"=>21000000.0, "quotes"=>{"USD"=>{"price"=>6592.56514166, "volume_24h"=>3990509859.95985, "market_cap"=>114043795501.0, "percent_change_1h"=>-0.31, "percent_change_24h"=>-0.36, "percent_change_7d"=>-0.61}}, "last_updated"=>1538393012}, "1027"=>{"id"=>1027, "name"=>"Ethereum", "symbol"=>"ETH", "website_slug"=>"ethereum", "rank"=>2, "circulating_supply"=>102298658.0, "total_supply"=>102298658.0, "max_supply"=>nil, "quotes"=>{"USD"=>{"price"=>229.147840966, "volume_24h"=>1701049487.13546, "market_cap"=>23441516679.0, "percent_change_1h"=>-0.8, "percent_change_24h"=>-2.56, "percent_change_7d"=>-2.44}}, "last_updated"=>1538393021}, "52"=>{"id"=>52, "name"=>"XRP", "symbol"=>"XRP", "website_slug"=>"ripple", "rank"=>3, "circulating_supply"=>39870907279.0, "total_supply"=>99991836919.0, "max_supply"=>100000000000.0, "quotes"=>{"USD"=>{"price"=>0.5790784377, "volume_24h"=>1229031882.79177, "market_cap"=>23088382697.0, "percent_change_1h"=>-1.6, "percent_change_24h"=>-4.58, "percent_change_7d"=>7.96}}, "last_updated"=>1538393043}, "1831"=>{"id"=>1831, "name"=>"Bitcoin Cash", "symbol"=>"BCH", "website_slug"=>"bitcoin-cash", "rank"=>4, "circulating_supply"=>17378475.0, "total_supply"=>17378475.0, "max_supply"=>21000000.0, "quotes"=>{"USD"=>{"price"=>532.361000338, "volume_24h"=>480935803.85542, "market_cap"=>9251622335.0, "percent_change_1h"=>-0.78, "percent_change_24h"=>-1.57, "percent_change_7d"=>13.15}}, "last_updated"=>1538393013}, "1765"=>{"id"=>1765, "name"=>"EOS", "symbol"=>"EOS", "website_slug"=>"eos", "rank"=>5, "circulating_supply"=>906245118.0, "total_supply"=>1006245120.0, "max_supply"=>nil, "quotes"=>{"USD"=>{"price"=>5.6494577239, "volume_24h"=>822687391.374753, "market_cap"=>5119793479.0, "percent_change_1h"=>-0.53, "percent_change_24h"=>-3.01, "percent_change_7d"=>-1.66}}, "last_updated"=>1538393011}, "512"=>{"id"=>512, "name"=>"Stellar", "symbol"=>"XLM", "website_slug"=>"stellar", "rank"=>6, "circulating_supply"=>18789958255.0, "total_supply"=>104323820467.0, "max_supply"=>nil, "quotes"=>{"USD"=>{"price"=>0.261922298, "volume_24h"=>67633971.9905846, "market_cap"=>4921509046.0, "percent_change_1h"=>0.14, "percent_change_24h"=>1.03, "percent_change_7d"=>-0.49}}, "last_updated"=>1538392997}, "2"=>{"id"=>2, "name"=>"Litecoin", "symbol"=>"LTC", "website_slug"=>"litecoin", "rank"=>7, "circulating_supply"=>58532552.0, "total_supply"=>58532552.0, "max_supply"=>84000000.0, "quotes"=>{"USD"=>{"price"=>60.7806370254, "volume_24h"=>461333051.026648, "market_cap"=>3557645805.0, "percent_change_1h"=>-0.07, "percent_change_24h"=>-1.17, "percent_change_7d"=>4.09}},

Answer 1

You could try this code and feedback please :)
<h1>LISTING </h1>
<% #jsonData.fetch('data', {}).each do |id, coin| %>
Name: <%= coin['name'] %> <br />
Symbol: <%= coin['symbol'] %> <br />
Website_slug: <%= coin['website_slug'] %> <br />
Rank: <%= coin['rank'] %> <br />
Circulating_supply: <%= coin['circulating_supply'] %> <br />
total_supply: <%= coin['total_supply'] %> <br />
max_supply: <%= coin['max_supply'] %> <br />
Price: <%= coin.dig('quotes', 'USD', 'price') %> <br />
Volume24h: <%= coin.dig('quotes', 'USD', 'volume_24h') %> <br />
Market_cap: <%= coin.dig('quotes', 'USD', 'market_cap') %> <br />
Change_1he: <%= coin.dig('quotes', 'USD', 'pricpercent_change_1he') %> <br />
Change_24h: <%= coin.dig('quotes', 'USD', 'percent_change_24h') %> <br />
Change_7d: <%= coin.dig('quotes', 'USD', 'percent_change_7d') %> <br />
<%end%>
<%end%>
This is a sample of your JSON:
{
"data":{
"1":{
"id":1,
"name":"Bitcoin",
"symbol":"BTC",
"website_slug":"bitcoin",
"rank":1,
"circulating_supply":17298850.0,
"total_supply":17298850.0,
"max_supply":21000000.0,
"quotes":{
"USD":{
"price":6592.56514166,
"volume_24h":3990509859.95985,
"market_cap":114043795501.0,
"percent_change_1h":-0.31,
"percent_change_24h":-0.36,
"percent_change_7d":-0.61
}
},
"last_updated":1538393012
},
"1027":{
"id":1027,
"name":"Ethereum",
"symbol":"ETH",
"website_slug":"ethereum",
"rank":2,
"circulating_supply":102298658.0,
"total_supply":102298658.0,
"max_supply":null,
"quotes":{
"USD":{
"price":229.147840966,
"volume_24h":1701049487.13546,
"market_cap":23441516679.0,
"percent_change_1h":-0.8,
"percent_change_24h":-2.56,
"percent_change_7d":-2.44
}
},
"last_updated":1538393021
},
"52":{
"id":52,
"name":"XRP",
"symbol":"XRP",
"website_slug":"ripple",
"rank":3,
"circulating_supply":39870907279.0,
"total_supply":99991836919.0,
"max_supply":100000000000.0,
"quotes":{
"USD":{
"price":0.5790784377,
"volume_24h":1229031882.79177,
"market_cap":23088382697.0,
"percent_change_1h":-1.6,
"percent_change_24h":-4.58,
"percent_change_7d":7.96
}
},
"last_updated":1538393043
},
"1831":{
"id":1831,
"name":"Bitcoin Cash",
"symbol":"BCH",
"website_slug":"bitcoin-cash",
"rank":4,
"circulating_supply":17378475.0,
"total_supply":17378475.0,
"max_supply":21000000.0,
"quotes":{
"USD":{
"price":532.361000338,
"volume_24h":480935803.85542,
"market_cap":9251622335.0,
"percent_change_1h":-0.78,
"percent_change_24h":-1.57,
"percent_change_7d":13.15
}
},
"last_updated":1538393013
},
"1765":{
"id":1765,
"name":"EOS",
"symbol":"EOS",
"website_slug":"eos",
"rank":5,
"circulating_supply":906245118.0,
"total_supply":1006245120.0,
"max_supply":null,
"quotes":{
"USD":{
"price":5.6494577239,
"volume_24h":822687391.374753,
"market_cap":5119793479.0,
"percent_change_1h":-0.53,
"percent_change_24h":-3.01,
"percent_change_7d":-1.66
}
},
"last_updated":1538393011
},
"512":{
"id":512,
"name":"Stellar",
"symbol":"XLM",
"website_slug":"stellar",
"rank":6,
"circulating_supply":18789958255.0,
"total_supply":104323820467.0,
"max_supply":null,
"quotes":{
"USD":{
"price":0.261922298,
"volume_24h":67633971.9905846,
"market_cap":4921509046.0,
"percent_change_1h":0.14,
"percent_change_24h":1.03,
"percent_change_7d":-0.49
}
},
"last_updated":1538392997
},
"2":{
"id":2,
"name":"Litecoin",
"symbol":"LTC",
"website_slug":"litecoin",
"rank":7,
"circulating_supply":58532552.0,
"total_supply":58532552.0,
"max_supply":84000000.0,
"quotes":{
"USD":{
"price":60.7806370254,
"volume_24h":461333051.026648,
"market_cap":3557645805.0,
"percent_change_1h":-0.07,
"percent_change_24h":-1.17,
"percent_change_7d":4.09
}
}
}
}
}
Following this json you can see that there are no arrays [] it just a nested hashes {} so no need for all of your loops. For ex. to get the price you need to do something like: #jsonData['data']['1']['quotes']['USD']['price']
This path ['data']['1']['quotes']['USD']['price'] is all static, which means it will be the same for every coin. the only dynamic/changing part is ['1']. Sometimes it will be ['1'], ['1027'], ['52'], etc.
So in my code you can see that I access all of the data staticly but only for the IDs I had to loop over it but this loop will be over key => value because as mentioned before we are dealing with hashes not arrays.
So when I did <% #jsonData.fetch('data', {}).each do |id, coin| %>:
id has the value of '1'.
coin has the structure of the coin (you can staticlly retrieve any piece of data like coin.dig('quotes', 'USD', 'price') for ex.
What you where doing:
<% #jsonData.['data'].each do |coin| %>:
coin will be ['1', 'structure of the coin here']
when you do coin['name'] this will return nil but won't fail. At this point you thought it's working but it is not.