Add Format A Hash Into A String Template as a Ruby TIL

ruby/format-a-hash-into-a-string-template.md

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+# Format A Hash Into A String Template
+
+The `%` method as defined by `String`
+([`String#%`](https://ruby-doc.org/core-3.0.0/String.html#method-i-25)) allows
+you to format (interpolate) an object or array of values into a string. That
+string needs to contain template markers for where the values should go.
+
+Here is an example of folding an array of values into a string with [`%s`
+format
+specifier](https://docs.ruby-lang.org/en/master/format_specifications_rdoc.html#label-Specifier+s):
+
+```ruby
+> User = Struct.new(:id)
+=> User
+> user1 = User.new(123)
+=> #<struct User id=123>
+> "%s ID: %s" % [user1.class.to_s, user1.id]
+=> "User ID: 123"
+```
+
+Or perhaps more usefully for a string that acts as a template, you can used
+named specifiers that correspond to hash keys:
+
+```ruby
+> template = "You paid %{formatted_price} for %{product}. Enjoy your purchase!"
+=> "You paid %{formatted_price} for %{product}. Enjoy your purchase!"
+
+> data = { product: "Ruby Explained™", formatted_price: "$38.99" }
+=> {:product=>"Ruby Explained™", :formatted_price=>"$38.99"}
+
+> template % data
+=> "You paid $38.99 for Ruby Explained™. Enjoy your purchase!"
+```
+
+[source](https://hashrocket.com/blog/posts/using-a-hash-of-data-for-string-replacement-in-ruby)