Add Get Specific Values From Hashes And Arrays as a Ruby TIL

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
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@@ -1345,6 +1345,7 @@ If you've learned something here, support my efforts writing daily TILs by
 - [Generate A Signed JWT Token](ruby/generate-a-signed-jwt-token.md)
 - [Generate Ruby Version And Gemset Files With RVM](ruby/generate-ruby-version-and-gemset-files-with-rvm.md)
 - [Get Info About Your RubyGems Environment](ruby/get-info-about-your-ruby-gems-environment.md)
+- [Get Specific Values From Arrays And Hashes](ruby/get-specific-values-from-hashes-and-arrays.md)
 - [Get The Output Of Running A System Program](ruby/get-the-output-of-running-a-system-program.md)
 - [Get UTC Offset For Different Time Zones](ruby/get-utc-offset-for-different-time-zones.md)
 - [Identify Outdated Gems](ruby/identify-outdated-gems.md)

ruby/get-specific-values-from-hashes-and-arrays.md

@@ -0,0 +1,44 @@
+# Get Specific Values From Hashes And Arrays
+
+Ruby defines a `#values_at` method on both `Hash` and `Array` that can be used
+to grab multiple values from an instance of either of those structures.
+
+Here is an example of grabbing values by key (if they exist) from a hash.
+
+```ruby
+> hash = {one: :two, hello: "world", four: 4}
+=> {one: :two, hello: "world", four: 4}
+> hash.values_at(:one, :four, :three)
+=> [:two, 4, nil]
+```
+
+And here is an example of grabbing values at specific indexes from an array, if
+those indexes exist.
+
+```ruby
+> arr = [:a, :b, :c, :d, :e]
+=> [:a, :b, :c, :d, :e]
+> arr.values_at(0, 3, 6)
+=> [:a, :d, nil]
+```
+
+Notice that in both cases, `nil` is returned for a key or index that doesn't
+exist.
+
+What I like about this method is that in a single call I can grab multiple
+named (or indexed) values and get a single array result with those values.
+
+One way I might use this with a JSON response from an API request could look
+like this:
+
+```ruby
+resp = client.getSomeData(id: 123)
+
+[status, body] = resp.values_at("status", "body")
+
+if status == 200
+  puts body
+end
+```
+
+[source](https://docs.ruby-lang.org/en/3.4/Hash.html#method-i-values_at)