Question

var mC = function(map){
    var init = function(iMap){
        alert("Init " + this + " with");
    }
    init(map);
};
var m = new mC({});

why i am getting value of this as [object window]? Is it a window object??

Answer 1

Yes! Because init is a variable of mC, it will share its scope (which currently is the global scope, which is also the window object).

However. If you changed to the following:

var mC = function(map){
    this.init = function(iMap){
        alert("Init " + this + " with");
    }
    this.init(map);
};
var m = new mC({});

Then this inside init would be a reference to your instance.