c# - how to get Json nested properties to primary one -

i have below scenario:

this class structure :

public class user {      public string firstname { get; set; }      public string lastname { get; set; }      public system.collections.objectmodel.collection<likes> likes { get; set; }  }  public class likes {      public string sport { get; set; }      public string music { get; set; }      public string food { get; set; }      public string place { get; set; }   } 

when serialize object of user class generate below json string :

{"firstname":"naresh",  "lastname":"parmar",  "likes": [{"sport":"cricket",             "music":"classic",             "food":"gujarati",              "place":"india"}] } 

i want generate above json string below:

{"firstname":"naresh",  "lastname":"parmar",  "sport":"cricket",  "music":"classic",  "food":"gujarati",  "place":"india" } 

i want nested properties primary one.

any appreciated.

thanks in advance..

edit:

 {"firstname":"naresh",   "lastname":"parmar",   "sport":"cricket,chess,football",   "music":"classic",   "food":"gujarati",   "place":"india"   } 

it's bad practice, since code i'll post bellow doesn't have great maintainability, if that's looking for, can use this. class have format you'd like, , have method adds list of likes format you've required. class should serialize json:

    class nesteduser     {         public string firstname { get; set; }          public string lastname { get; set; }          public string sport { get; set; }          public string music { get; set; }          public string food { get; set; }          public string place { get; set; }          public void addlikes(system.collections.objectmodel.collection<likes> likes)         {             foreach (likes in likes)             {                 sport += like.sport + ",";                 music += like.music + ",";                 food += like.food + ",";                 place += like.place + ",";             }              if (sport != string.empty)             {                 sport = sport.substring(0, sport.length - 1);             }             if (music != string.empty)             {                 music = music.substring(0, music.length - 1);             }             if (food != string.empty)             {                 food = food.substring(0, food.length - 1);             }             if (place != string.empty)             {                 place = place.substring(0, place.length - 1);             }         }     }