index.erb
<head>
<%= csrf_meta_tags %>
</head>
<form action="result" method ="POST">
<input type="number" name="num1"> + <input type="number" name="num2">
<input type="submit">
</form>
html 작성
home_controller.rb
class HomeController < ApplicationController
def index
end
def result
@plus_result = params[:num1].to_i + params[:num2].to_i
end
end
params[:num1] => num1 이라는 name 의 value 를 가져옴 => 문자열 형태
.to_i => int 형변환
routes.rb
연결