index.html.erb

<h1>How remote true works</h1>

<%= form_tag remote: true  do %>
	<%= text_field_tag "name" %>
	<%= submit_tag "sumit you name" %>
<% end %>


<div style="border: 1px red solid" id="names">
	<%= @names %>
</div>

index.js.erb

$("#names").append("<%= escape_javascript(render @names) %>");

routes.rb

Rails.application.routes.draw do
  get 'welcome/index'
  post 'welcome/index'
end

welcome_controller.rb

class WelcomeController < ApplicationController
  def index
  	@names = params[:name]
  end
end