How do you know if a value is a list?

How to know if a value in this Json is of type List?

 foreach (string nameObj in j.keys)
 {
     //if(Control if nameObj is of type list)
     foreach (JSONObject value in j.GetField(nameObj).list)
     {
         string[] c = value.ToString().Replace ("\"", "").Split (',');
         Vector3 coo = new Vector3 (System.Convert.ToSingle(c[0]),System.Convert.ToSingle(c[1]),0);
 
                     if(nameObj == "Robot")
                     {
                         //code instructions
                     }
                     else if(nameObj.Contains("Platf"))
                     {
                         //code instructions
                     }