Ruby Language ERB


ERB stands for Embedded Ruby, and is used to insert Ruby variables inside templates, e.g. HTML and YAML. ERB is a Ruby class that accepts text, and evaluates and replaces Ruby code surrounded by ERB markup.


  • <% number = rand(10) %> this code will be evaluated
  • <%= number %> this code will be evaluated and inserted into the output
  • <%# comment text %> this comment will not be evaluated



  • ERB as a template: Abstract business logic into accompanied helper code, and keep your ERB templates clean and readable for people without Ruby knowledge.
  • Append files with .erb: e.g. .js.erb, .html.erb, .css.erb, etc.