json Ruby - TypeError：没有将哈希隐式转换为字符串
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Ruby - TypeError: no implicit conversion of Hash into String
提问by Mark Boulder
Trying to parse some JSON, byt why is textempty?
试图解析一些 JSON，为什么是text空的？
Desired output:
期望的输出：
textshould return Hello world\n\nApple, Harbor\n\nBanana, Kitchen\n\nMango, Bedroom
text应该回来 Hello world\n\nApple, Harbor\n\nBanana, Kitchen\n\nMango, Bedroom
text = "Hello world"
json = '{"fruits": [{"name": "Apple", "location": "Harbor"}, {"name": "Banana", "location": "Kitchen"}, {"name": "Mango", "location": "Bedroom"}]}'
fruits = JSON.parse(json)
def format_fruits(fruits)
fruits.each do |fruit|
puts "\n\n#{ fruit[0]['name'] }, #{ fruit[0]['location'] }"
end.to_sentence
end
text += format_fruits(fruits)
text
Current output:
电流输出：
TypeError: no implicit conversion of Hash into String
from (irb):5:in `+'
from (irb):5
from /home/mark/.gem/ruby/2.1.1/gems/railties-4.1.7/lib/rails/commands/console.rb:90:in `start'
from /home/mark/.gem/ruby/2.1.1/gems/railties-4.1.7/lib/rails/commands/console.rb:9:in `start'
from /home/mark/.gem/ruby/2.1.1/gems/railties-4.1.7/lib/rails/commands/commands_tasks.rb:69:in `console'
from /home/mark/.gem/ruby/2.1.1/gems/railties-4.1.7/lib/rails/commands/commands_tasks.rb:40:in `run_command!'
from /home/mark/.gem/ruby/2.1.1/gems/railties-4.1.7/lib/rails/commands.rb:17:in `<top (required)>'
from /home/mark/.gem/ruby/2.1.1/gems/activesupport-4.1.7/lib/active_support/dependencies.rb:247:in `require'
from /home/mark/.gem/ruby/2.1.1/gems/activesupport-4.1.7/lib/active_support/dependencies.rb:247:in `block in require'
from /home/mark/.gem/ruby/2.1.1/gems/activesupport-4.1.7/lib/active_support/dependencies.rb:232:in `load_dependency'
from /home/mark/.gem/ruby/2.1.1/gems/activesupport-4.1.7/lib/active_support/dependencies.rb:247:in `require'
from /home/mark/myapp/bin/rails:8:in `<top (required)>'
from /home/mark/.gem/ruby/2.1.1/gems/activesupport-4.1.7/lib/active_support/dependencies.rb:241:in `load'
from /home/mark/.gem/ruby/2.1.1/gems/activesupport-4.1.7/lib/active_support/dependencies.rb:241:in `block in load'
from /home/mark/.gem/ruby/2.1.1/gems/activesupport-4.1.7/lib/active_support/dependencies.rb:232:in `load_dependency'
from /home/mark/.gem/ruby/2.1.1/gems/activesupport-4.1.7/lib/active_support/dependencies.rb:241:in `load'
from /home/mark/.gem/ruby/2.1.1/gems/spring-1.1.3/lib/spring/commands/rails.rb:6:in `call'
from /home/mark/.gem/ruby/2.1.1/gems/spring-1.1.3/lib/spring/command_wrapper.rb:38:in `call'
from /home/mark/.gem/ruby/2.1.1/gems/spring-1.1.3/lib/spring/application.rb:180:in `block in serve'
from /home/mark/.gem/ruby/2.1.1/gems/spring-1.1.3/lib/spring/application.rb:153:in `fork'
from /home/mark/.gem/ruby/2.1.1/gems/spring-1.1.3/lib/spring/application.rb:153:in `serve'
from /home/mark/.gem/ruby/2.1.1/gems/spring-1.1.3/lib/spring/application.rb:128:in `block in run'
from /home/mark/.gem/ruby/2.1.1/gems/spring-1.1.3/lib/spring/application.rb:122:in `loop'
from /home/mark/.gem/ruby/2.1.1/gems/spring-1.1.3/lib/spring/application.rb:122:in `run'
from /home/mark/.gem/ruby/2.1.1/gems/spring-1.1.3/lib/spring/application/boot.rb:18:in `<top (required)>'
from /home/mark/.rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /home/mark/.rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from -e:1:in `<main>'irb(main):006:0> text
=> "Hello world"
irb(main):007:0>
采纳答案by Matt
The error is a result of calling Array#to_sentenceon a hash.
该错误是调用Array#to_sentence散列的结果。
Here's a fixed-up version with comments denoting the changes:
这是一个修复版本，带有表示更改的注释：
require 'json'
text = "Hello world"
json = '{"fruits": [{"name": "Apple", "location": "Harbor"}, {"name": "Banana", "location": "Kitchen"}, {"name": "Mango", "location": "Bedroom"}]}'
fruits = JSON.parse(json)['fruits'] # append ['fruits']
def format_fruits(fruits)
fruits.map do |fruit| # change each -> map
"\n\n#{ fruit['name'] }, #{ fruit['location'] }" # delete puts, [0]
end.join # change to_sentence -> join
end
text += format_fruits(fruits)
puts text
Output:
输出：
Hello world
Apple, Harbor
Banana, Kitchen
Mango, Bedroom
回答by shivam
In-case your json always contains "fruits" key, you can achieve this quite easily. Here:
如果你的 json 总是包含“fruits”键，你可以很容易地做到这一点。这里：
fruits = JSON.parse(json)
#=> {"fruits"=>[{"name"=>"Apple", "location"=>"Harbor"}, {"name"=>"Banana", "location"=>"Kitchen"}, {"name"=>"Mango", "location"=>"Bedroom"}]}
fruits["fruits"].each { |hash|
puts "\n\n#{hash['name']}, #{hash['location']}"
}
Another way to do this without using fruitskey:
另一种不使用fruits密钥的方法：
fruits.values.first.each { |hash|
puts "\n\n#{hash['name']}, #{hash['location']}"
}
