Once you have a JArray you can treat it just like any other Enumerable object, and using linq you can access them, check them, verify them, and select them.
var str = @"[1, 2, 3]";
var jArray = JArray.Parse(str);
Console.WriteLine(String.Join("-", jArray.Where(i => (int)i > 1).Select(i => i.ToString())));