c# - Convert List of object into another List of object -

i have list as

class vachel { int id{get;set;} int vachelid {get;set;} string title {get;set;} } 

list of vachel as

id  vachelid  title 1   2         bus 1   3         truck 2   4         cycle 2   5         bike 2   5         bick 

and want convert list<vachel> list<result>

class result { int id{get;set;} string vachelid {get;set;} string title {get;set;} } 

and result must as

   id   vachelid    title     1   2,3         bus,truck     2   4,5         cycle,bike,bick 

i tried as

list<vachel> v = getlist(); list<result> r = null;  r = v.groupby(x=> new{x.vachelid})     .select        (        x=> new result          {          id  =x.key.id,          vachelid =x.firstordefault().vachelid,          title   =x.firstordefault().title          }        ).tolist(); 

here know want put instead of .firstordefault().vachelid , .firstordefault().title don't know do.

r = v.groupby(x => x.id)      .select(g => new result(){         id = g.key,         vachelid = string.join(",", g.select(x => x.vachelid).distinct()),         title = string.join(",", g.select(x => x.title).distinct()),      }).tolist();