在rails get请求中将param作为数组传递，而不是字符串

?tags[]=ruby&tags[]=rails&tags[]=web

params[:tags] # => ["ruby", "rails", "web"]

// 使用URLSearchParams构建查询字符串
const params = new URLSearchParams();
['ruby', 'rails', 'web'].forEach(tag => {
  params.append('tags[]', tag);
});

// 最终URL
const url = `/search?${params.toString()}`;

class SearchController < ApplicationController
  def index
    @tags = params[:tags] || []
    # @tags 现在是数组形式
  end
end

<%= form_with url: search_path, method: :get do |f| %>
  <%= hidden_field_tag 'tags[]', 'ruby' %>
  <%= hidden_field_tag 'tags[]', 'rails' %>
  <%= submit_tag 'Search' %>
<% end %>

?tags=ruby,rails,web

params[:tags] # => "ruby,rails,web" (字符串)

# 编码
CGI.escape('ruby on rails') # => "ruby+on+rails"

# 解码
URI.decode_www_form_component("ruby+on+rails") # => "ruby on rails"

?user[tags][]=frontend&user[tags][]=backend

params[:user][:tags] # => ["frontend", "backend"]

params[:tags] == params['tags'] # => true

params.permit(tags: [])