radio buttons and checkboxes

test.erb

<h1>Test</h1>

<% if !@p.nil? %>
  <%= @p.inspect %>
<% end %>

<form method="post" action="/">
  <h2>Have you ever smoked?</h2>
  <p>
    <input type="radio" name="smoker" value="Yes"> Yes<br>
    <input type="radio" name="smoker" value="No"> No<br>
  </p>

  <h2>Injury</h2>
  <p>
    <input type="checkbox" name="injury[]" value="Neck"> Neck<br>
    <input type="checkbox" name="injury[]" value="Shoulders"> Shoulders<br>
    <input type="checkbox" name="injury[]" value="Knee"> Knee<br>
  </p>

  <input type="submit" value="Go">
</form>

test.rb

require 'sinatra'

get '/' do
  erb :test, layout: false
end

post '/' do
  @p = params
  erb :test, layout: false
end