Prototype examples

examples_prototype.js

function Triangle() {
  this.a;
  this.b;
  this.c;
  this.setSides = function(a, b, c) {
    this.a = a;
    this.b = b;
    this.c = c;
  };

  this.toString = function() {
    console.log(" A " + this.a + " B " + this.b + " C " + this.c);
  };
}

var t = new Triangle();
t.setSides(20, 30, 44);
//t.toString();

function Equilateral() {

}
Equilateral.prototype = new Triangle();
Equilateral.prototype.setSides = function(a) {
  this.a = a;
  this.b = a;
  this.c = a;
}

var eq = new Equilateral();
eq.setSides(50);
eq.toString();