Javascript class, constructor and seed value -

on below query me going , clarify many doubts. far, read have class in js through function statements, , json notation hold object values. so, in below code

1. how write testdata variable holds shape values

2. how initialize shape objects testdata. may able create object assigning each member

   var obj = {             x: testdata[i].x,               y: testdata[i].y,             ...               }; 

is proper way, or can use constructors described here

var testdata = [ {}, {} ]   //shape class  var shape = function(x, y, w, h) {         this.x = x;         this.y = y;         this.w = w;         this.h = h;         this.calculatearea = function() {             alert("area.."); };   func test() { var arr = []; (var i=0,l=testdata.length; i<l; i++) {        var s = testdata[i];            var obj = // how construct shape object here  through constructor                   }; arr.push(obj);  } 

you can construct new object (a shape, in case) new keyword. use:

var obj = new shape(testdata[i].x, testdata[i].y, testdata[i].w, testdata[i].h);