c# - Second Enemy object not acting like the first enemy -

how come when add new enemy object list of objects loaded game, second 1 doesn't move around screen first one?

objlist code

class items {     public static list<obj> objlist = new list<obj>();      public static void initialize()     {         objlist.add(new player(new vector2(50, 50)));         objlist.add(new enemy(new vector2(500, 500)));         objlist.add(new enemy(new vector2(600, 200)));         objlist.add(new blueball(new vector2(300, 400)));         objlist.add(new greenball(new vector2(350, 100)));         objlist.add(new orangeball(new vector2(900, 250)));         objlist.add(new pinkball(new vector2(100, 500)));         objlist.add(new redball(new vector2(600, 500)));         objlist.add(new yellowball(new vector2(500, 250)));      } 

the third entry in list second enemy wish load game. first 1 works should second enemy doesn't move around screen first. below enemy class movement code.

enemy class

class enemy : obj {     float spd = 1;     float detectiondistance = 175;      public enemy(vector2 pos)         : base(pos)     {         position = pos;         spritename = "blackball";         speed = spd;     }      public override void update()     {         rotation = point_direction(position.x, position.y, player.player.position.x, player.player.position.y);         speed = math.abs(player.player.position.x - position.x) < 175 && math.abs(player.player.position.y - position.y) < 230 ? spd : 0;          base.update();     }        public override void pushto(float pix, float dir)     {         float newx = (float)math.cos(mathhelper.toradians(dir));         float newy = (float)math.sin(mathhelper.toradians(dir));         newx *= pix;         newy *= pix;         if (!collision(new vector2(newx, newy), new player(vector2.zero)))         {             base.pushto(pix, dir);         }     }      //uses trig calculate shortest distance player moves towards position     private float point_direction(float x, float y, float x2, float y2)     {         float diffx = x - x2;         float diffy = y - y2;         float adj = diffx;         float opp = diffy;         float tan = opp / adj;         float res = mathhelper.todegrees((float)math.atan2(opp, adj));         res = (res - 180) % 360;         if (res < 0) { res += 360; }         return res;     } } 

the line speed = math.abs(player.player.position.x - position.x) < 175 && math.abs(player.player.position.y - position.y) < 230 ? spd : 0; enemy supposed do, move towards player if within radius of 175 doesn't seem working on second enemy , can't see why.

objects updated in game1.cs

protected override void update(gametime gametime)     {         foreach (obj o in items.objlist)         {             o.update();         } 

object class

class obj : microsoft.xna.framework.game {     public vector2 position;     public float rotation = 0.0f;     public texture2d spriteindex;     public string spritename;     public float speed = 0.0f;     public float scale = 1.0f;     public bool alive = true;     public rectangle area;     public bool solid = false;      public int score;      public obj(vector2 pos)     {         position = pos;     }      private obj()     {      }       public virtual void update()     {             if (!alive) return;              updatearea();             pushto(speed, rotation);         }         public virtual void loadcontent(contentmanager content)     {         spriteindex = content.load<texture2d>("sprites\\" + spritename);         area = new rectangle((int)position.x - (spriteindex.width / 2), (int)position.y - (spriteindex.height / 2), spriteindex.width, spriteindex.height);     }       public virtual void draw(spritebatch spritebatch)     {          if (!alive) return;          rectangle size;         vector2 center = new vector2(spriteindex.width / 2, spriteindex.height / 2);         spritebatch.draw(spriteindex, position, null, color.white, mathhelper.toradians(rotation), center, scale, spriteeffects.none, 0);      }      public bool collision(vector2 pos, obj obj)     {         rectangle newarea = new rectangle(area.x, area.y, area.width, area.height);         newarea.x += (int)pos.x;         newarea.y += (int)pos.y;          foreach (obj o in items.objlist)         {             if (o.gettype() == obj.gettype() && o.solid)                 if (o.area.intersects(newarea))                     return true;         }         return false;     }      public obj collision(obj obj)     {         foreach (obj o in items.objlist)         {             if (o.gettype() == obj.gettype())                 if (o.area.intersects(area))                     return o;         }         return new obj();     }      public void updatearea()     {         area.x = (int)position.x - (spriteindex.width / 2);         area.y = (int)position.y - (spriteindex.height / 2);     }      public t checkcollisionagainst<t>() t : obj     {         // if collision detected, returns colliding object; otherwise null.         return items.objlist             .oftype<t>()             .firstordefault(o => o.area.intersects(area));     }      public virtual void pushto(float pix, float dir)     {         float newx = (float)math.cos(mathhelper.toradians(dir));         float newy = (float)math.sin(mathhelper.toradians(dir));         position.x += pix * (float)newx;         position.y += pix * (float)newy;     } }