I have a SuperClass with info as an instance variable. SuperClass has function printInfo(). printInfo() needs to access instance variable info.
I want to create a SubClass which also has method printInfo(). I want to call printInfo() of SuperClass from printInfo() of SubClass.

SuperClass = function()

{

    this.info = I am superclass;

    console.log(SuperClass:);

};



SuperClass.prototype.printInfo = function(that)

{

    console.log(printing from superclass printInfo);

    console.log(that.info);

};



SubClass = function(){};



SubClass.prototype = new SuperClass();



SubClass.prototype.printInfo = function()

{

    console.log(calling superclass);

    this.constructor.prototype.printInfo(this);

    console.log(called superclass);

};



var sc = new SubClass();

sc.printInfo();

You can see that I am passing that as a parameter to printInfo. Without that parameter, info is printed as undefined. Like in the following case, this.info is undefined when this function is called from object of SubClass.

SuperClass.prototype.printInfo = function()

    {

        console.log(printing from superclass printInfo);

        console.log(this.info);

    };

What is the proper way to override and invoke methods of superclass in javascript, enabling functions to access instance variables of the class?