inheritance - how does javascript private variable work in prototype implementation -


http://msdn.microsoft.com/en-us/magazine/ff696765.aspx

this website shows example

function circle(radius) {   this.getradius = function() {     return radius;   };   this.setradius = function(value) {     if (value < 0) {       throw new error('radius should of positive value');     }     radius = value;   }; }

vs

circle.prototype.getradius = function() {   return this._radius; }; circle.prototype.setradius = function(value) {   if (value < 0) {     throw new error('radius should of positive value');   }   this._radius = value; };

and on page states

"however, in such case, lose luxury of having private members, , have resort other means such denoting privacy through convention (underscored property names). comes down making choice between having private members or having more efficient implementation."

how using prototype this._ losing luxury of "truly private" members?, prototype.this not considered reference self?

if property on object visible code in function on prototype object, it's visible code anywhere.


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