SharePoint Person/Group Column with REST API

With SharePoint REST API you can iterate through all columns. But what happens when you want to display a Person/Group column like the Author? You will get a User ID as a result.

To display the “Authors Full Name” instead of the ID just use the parameter $expand.

var listname = "My List";
var url =  _spPageContextInfo.webAbsoluteUrl + 
  "/_api/web/lists/getbytitle('"+listName+"')/items?
  "$select=Id,Title,Created,Author/Title&amp"+;
  "$top=20&amp"+;
  "$orderby=Created desc&amp"+;
  "$expand=Author";
...
$.ajax({
 url: url ,
 method: "GET",
 headers: {"Accept": "application/json; odata=verbose" },
 success: function (data) {
   if(data.d.results.length >0){
    for (var i = 0; i < data.d.results.length; i++){
     data.d.results[i].Author.Title
    }
   }
 }
...

And if you need to use the filter based on the Person/Group column here is how to declare it:

var urlPI = _spPageContextInfo.webAbsoluteUrl +
       "/_api/web/lists/getbytitle('"+listName+"')/items?"+
       "$select=Author,Author/Title"+
       "$top=5000"+
       "$orderby=Created desc"+
       "$expand=Author&"+
       "$filter=Author eq '"+_spPageContextInfo.userId+"'";

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