How to count number of elements in a JSON array in Delphi
The items field is an array, so retrieving it as a string is just wrong, so it makes sense that reading the array count via a string length would not work.
Try this instead:
uses ..., System.JSON;var JSONBook, JSONItem: TJSONObject; JSONItems: TJSONArray; CountItems: integer;begin JSONBook := RESTResponse1.JSONValue as TJSONObject; JSONItems := JSONBook.GetValue('items') as TJSONArray; CountItems := JSONItems.Count; ShowMessage(IntToStr(CountItems)); for i := 0 to CountItems-1 do begin JSONItem := JSONItems.Items[i] as TJSONObject; ... end;end;