c# - Get Distinct values out of List<Object> -

i have list contains instances of beam class. each of these beam objects has elevation property.

list<beam> beams = new list<beam> {beam1, beam2, ...};  public class beam {     public double elevation; } 

now want create list<double> contains distinct elevations. example how write method accepts beams list below

var beam1 = new beam { elevation = 320); var beam2 = new beam { elevation = 320); var beam3 = new beam { elevation = 640); var beam4 = new beam { elevation = 0);  list<beam> beams = new list<beam> {beam1, beam2, beam3, beam4}; 

and gives removing duplicate elevations:

listofelevations = {0, 320,640} 

1) make beam implement icomparable:

public class beam : icomparable {     public double elevation; //consider changing property, btw.      public int compareto(object obj) {          if (obj == null) return 1;           beam otherbeam = obj beam;          return this.elevation.compareto(otherbeam.elevation);     } } 

2) use distinct():

var listofelevations = beams.distinct().select(x=> x.elevation).tolist();