About JSON. How to use rails format.json?@stackoverflow.

format_json.md

How to use rails format.json? @Stackoverflow

def index
	@cellphones = Cellphone.all

	respond_to do |format|
	format.html
	format.json { render json: @cellphoes }
end

• what is format.json used for?
• do I have to create a view for it?
• how does it relate to javascrip?
• how does it relate to ajax?
• please give a simple example of how to use it...

1. It's used to return JSON.
2. No, it renders @cellphones as JSON. You may create a view, though, for example, using a JSON builder to customize the output beyond what Rails provides out of the box.
3. JavaScript is often used to make JSON Ajax requests, like for client-side frameworks.
4. Ajax calls often want JSON as a result. They may also request HTML to render directly.
5. That is an example of how to use it; make an Ajax request to /cellphones.