render-callback.md

id	render-callback
sidebar_label	Render callback
title	Render Callback
description	Render callback | React Patterns, techniques, tips and tricks in development for React developers.
keywords	render callback reactpatterns react patterns reactjspatterns reactjs patterns react reactjs react techniques react tips and tricks
version	Render callback
image	/img/reactpatterns-cover.png

For example below, notice that we create a function foo which takes a callback function as a parameter. When we call foo, it turns around and calls back to the passed-in function.

const foo = (hello) => {
  return hello('foo')
}

foo((name) => {
  return `hello from ${name}`
})

// hello from foo

As you can see, foo used the callback function to complete a portion of a string.

In the React world, a render callback works the same way, but returning a portion of the rendered markup.