Accessing variable inside object property

Question

So I encountered a problem. I have this object called myTree. And that object has properties. One of the properties contains a method like this:

Answer 1

JavaScript variables are function-scoped. It is not possible to access variables belonging to an inner scope (i.e. "function") from an outer scope.

If you want that kind of access, you must make the respective variable part of the outer scope.

var myTree = function() {
  var myarray = [];

  this.prep = function (variable) {
    myarray.push(variable);
  };
}

In your scenario, where you have nested objects, it's quite similar:

var myTree = {
  myarray: [],
  prep: function (variable) {
    this.myarray.push(variable);
  }
}

The only difference is the use of the this keyword.

When you define an object via the object literal syntax (obj = {prop: value}) instead of via a constructor (function Obj(value) { this.prop = value; }; obj = new Obj(value);), then all defined properties will be "public" by default.

When you call a function on that object, this will point to the respective object instance.

Accessing an "inner scope" variable from outside is still impossible. There's no way around that.

Generally speaking: You can access properties of the objects you construct. You can never access function local variables (except from the inside of nested functions).