render-callback.md

Render Callback

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.