Using ArcGIS Javascript API and need help understanding asynchronous programming in accessing the fields property of a FeatureLayer Object

What is ArcGIS API for JavaScript?

The ArcGIS API for JavaScript is a lightweight way to embed maps and tasks in web applications. You can get these maps from ArcGIS Online, your own ArcGIS Server or others’ servers.

Is ArcGIS API for JavaScript free?

The JavaScript API is hosted by Esri and is available for free use, please read the Terms of Use – FAQ for more info.

How do I add a feature layer in ArcGIS JS?

Add a line feature layer
Go to the Trails URL and browse the properties of the layer . Make note of the Name, Type, Drawing Info, and Fields properties. In CodePen, create a FeatureLayer and set the url property. Add line.