Ruby 2.15中使用each循环访问哈希元素报错，如何正确处理？

Hey there! Let's break down why you're hitting that TypeError and get your hash iteration working correctly.

First, let's recap your setup: you've got an outer hash test, where the key "foo" maps to an inner hash with id, lobbyist_id, and organization_id keys. The structure looks like this:

{ "foo" => { "id" => 5, "lobbyist_id" => 19, "organization_id" => 8 } }

The mistake here is how you're using each on the outer hash. In Ruby, when you call each on a hash, the block receives a two-element array representing each key-value pair (like ["foo", {"id"=>5, ...}] for your case). When you tried t["id"], you were treating that array like a hash—arrays only accept integer indices, hence the "no implicit conversion of String into Integer" error.

Correct Implementation Options #

Here are two clean ways to access that id value properly:

Option 1: Explicitly capture key and value #

This is the most readable approach—just split the key-value pair into separate variables in your block:

test.each do |key, inner_hash|
  puts inner_hash["id"]
end

Here, key will be "foo" (you can ignore it if you don't need it), and inner_hash is the actual hash containing the id you want. Accessing inner_hash["id"] will give you 5 as expected.

Option 2: Access the value via array index #

If you prefer to keep a single block parameter, you can grab the value from the key-value array using index 1 (since index 0 is the key):

test.each do |key_value_pair|
  puts key_value_pair[1]["id"]
end

Quick note: The code you mentioned (test.each do |t| t.each do |t1| puts t1["id"] end end) won't work—because t is the key-value array, iterating over it will loop through "foo" (a string) and the inner hash. When it gets to "foo", trying t1["id"] will throw the same type error again.

内容的提问来源于stack exchange，提问作者EastsideDev