javascript - Array in Node.js, how to work with it -

i'm newbye in web programming , more in javascript, i'm trying learn learn node.js, , found strange error... i've got code:

var structobject = function(type, title, isreplicable, isvisible) {     this._type = type;     this._title = title;     this._childelements = new array();     this._isreplicable = isreplicable;     this._id = 0;  //todo };  structobject.prototype.addchild = function (element) {     structobject._childelements.push(element); };  structobject.prototype.stringify = function () {     console.log("main element: "+this._title);     (var i=0;i<this._childelements.length;i++) {         console.log("child "+i+": "+this._childelements[i]._title);     } };  structo1 = new structobject(1, "element1", true, true); structo1.addchild(new structobject(2, "element2", true, true)); structo1.stringify(); 

i've got problem here... may see, _childelements intended array, , i've got function addchild should add child element it.

the rest of code works, gives me following error:

c:\zerok\devcenter\structify\public_html\js\object.js:22   structobject._childelements.push(element);                              ^ typeerror: cannot read property 'push' of undefined 

why childelements not defined? tried not defining variable, , tried equaling this._childelements = []; none of these ways seem work either.

what should can work dynamically array?

structobject._childelements.push(element); 

you're trying modify (non-existent) _childelements property of constructor function instead of instance created new structobject.

use this instead of structobject on line.

---

it conventional, in javascript, use variables starting capital letters constructor functions.

var structobject = function(...) { 

would better written as:

var structobject = function(...) { 

or (since constructor makes objects):

var struct = function(...) { 

or (because named functions easier deal in debuggers):

function struct (...) {