Question

I need a function to work for only the given object. I’m not sure if its possible, but I tried something like:

var a = {
    b: function(a) {
        return display(a)
    }
}
a.prototype.display = function(a) {
    return a;
}
alert(a.b('Hi'))​//This is suppose to work
alert(display(a))//This isn't suppose to work

This doesn’t work though, not sure why. I’m kinda new to prototype. I used it with String.prototype for example but all the other stuff I still need to learn. Thanks for the help.

Answer 1

You need a private method in your object. The only way to achieve this in javascript is to keep the function in closure and execute it in the context of current object.

var a = (function () {
      var display = function (a) {
          return a;
      };

      return {
         b : function(a) {
             // display exist in closure scope of b;
             //executing display in the context of current object
             return display.apply(this, arguments);
         }
      };
})();

Here display is not accessible outside.

alert(a.b("hi")); //will return hi

a.display("hi"); is not accessible.