This example shows how to share property between class instances and use static methods. We need to use 'for' loop instead of Array.prototype.concat because in case we'll use 'concat' method, we'll assign static array to instance of class, not to prototype of class constructor. So, we need to loop over an array and use 'push' method.

  1. function MyObject(title){
  2.     this.title = title;
  3.     this.test = function() {
  4.         console.log('test from ' + this.title);
  5.         console.log(this.staticItemsMember.join(' - '));
  6.     }
  7. }
  8.  
  9.  
  10. MyObject.prototype = {
  11.     staticItemsMember   : [1, 2, 3],
  12.     addItems            : function(items) {
  13.         var title = this.title || 'was called from constructor method',
  14.             i = 0, l;
  15.         console.log('add items in function of class instance (' + title + ')');
  16.         if (!(items instanceof Array)) {
  17.             items = [items];
  18.         }
  19.         for (l = items.length; i < l; i++) {
  20.                     this.staticItemsMember.push(items[i]);   
  21.         }
  22.     }
  23. }
  24.  
  25.  
  26.  
  27. MyObject.addItems = function(items) {
  28.     console.log('add items in function of class constructor');
  29.     this.prototype.addItems(items);
  30. }
  31.  
  32.  
  33. var o = new MyObject('o');
  34. o.test();
  35. MyObject.addItems([5, 6]);
  36. o.test();
  37. o.addItems([8, 9, 10]);
  38. o.test();
  39. MyObject.addItems(11);
  40. o.test();
  41. var m = new MyObject('m');
  42. m.test();
  43. m.addItems([12, 13]);
  44. o.test();
  45. m.test();
  46. MyObject.addItems([14, 15, 16, 17]);
  47. m.test();
  48. o.test();
  49. o.addItems([18, 19, 20]);
  50. m.test();
  51. o.test();


This will output in browser's console text like: 
  1.  
  2.  
  3. >>> function MyObject(title){     this.title = title...); o.addItems([18, 19, 20]); m.test(); o.test();
  4.  
  5. test from o
  6.  
  7. 1 - 2 - 3
  8.  
  9. add items in function of class constructor
  10.  
  11. add items in function of class instance (was called from constructor method)
  12.  
  13. test from o
  14.  
  15. 1 - 2 - 3 - 5 - 6
  16.  
  17. add items in function of class instance (o)
  18.  
  19. test from o
  20.  
  21. 1 - 2 - 3 - 5 - 6 - 8 - 9 - 10
  22.  
  23. add items in function of class constructor
  24.  
  25. add items in function of class instance (was called from constructor method)
  26.  
  27. test from o
  28.  
  29. 1 - 2 - 3 - 5 - 6 - 8 - 9 - 10 - 11
  30.  
  31. test from m
  32.  
  33. 1 - 2 - 3 - 5 - 6 - 8 - 9 - 10 - 11
  34.  
  35. add items in function of class instance (m)
  36.  
  37. test from o
  38.  
  39. 1 - 2 - 3 - 5 - 6 - 8 - 9 - 10 - 11 - 12 - 13
  40.  
  41. test from m
  42.  
  43. 1 - 2 - 3 - 5 - 6 - 8 - 9 - 10 - 11 - 12 - 13
  44.  
  45. add items in function of class constructor
  46.  
  47. add items in function of class instance (was called from constructor method)
  48.  
  49. test from m
  50.  
  51. 1 - 2 - 3 - 5 - 6 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17
  52.  
  53. test from o
  54.  
  55. 1 - 2 - 3 - 5 - 6 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17
  56.  
  57. add items in function of class instance (o)
  58.  
  59. test from m
  60.  
  61. 1 - 2 - 3 - 5 - 6 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20
  62.  
  63. test from o
  64.  
  65. 1 - 2 - 3 - 5 - 6 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20