javascript class

Question

Can I somehow shorten this code?

var result = document.getElementById("result");

function Circle(pi, r) {
this.pi = pi;
this.r = r;
this.print1 = function() {

}
}

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

function Rectangle(x, y) {
this.x = x;
this.y = y;
}

Circle.prototype.calcArea = function() {
result.innerHTML += "Pole tego koła wynosi: " + this.pi * this.r * this.r + "cm2" + "<br>";
}

Circle.prototype.calcCircuit = function() {
result.innerHTML += "Obwód tego koła wynosi: " + 2 * this.pi * this.r + "<hr>";
}

Triangle.prototype.calcArea = function() {
result.innerHTML += "Pole tego trójkata wynosi: " + this.a * this.h / 2 + "cm2" + "<br>";
}

Triangle.prototype.calcCircuit = function() {
result.innerHTML += "Obwód tego trójkąta wynosi: " + (this.a + this.b + this.c) + "<hr>";
}

Rectangle.prototype.calcArea = function() {
result.innerHTML += "Pole tego prostokąta wynosi: " + this.x * this.y + "cm2" + "<br>";
}

Rectangle.prototype.calcCircuit = function() {
result.innerHTML += "Obwód tego prostokąta wynosi: " + 2 * (this.x + this.y) + "<hr>";
}

var circle = new Circle(3.14, 5);
var triangle = new Triangle(3, 4, 5, 6);
var rectangle = new Rectangle(6, 7);

circle.calcArea();
circle.calcCircuit();
triangle.calcArea(

Answer 1

Hmm, maybe not shorter, but cleaner?
Whenever we notice patterns in our code we should try and abstract them away.

Six times we output to the screen - three "Obwód" things, and three "Pole" things. The only thing differing is the name ("koła", "trójkata", "prostokąta") and the fomulas. Also, pi is already available as Math.PI!

So what I would do:
- Seperate out the name
- Seperate out the writing to result

Like this: http://lpaste.net/4433155223048945664

Answer 2

thank you, great job!!!

Answer 3

another question ... how can round this result?