var a = [{ x: 0, y: 0, color: "green", value: undefined, weight: 1 }, { x: 0, y: 1, color:   "red", value: undefined, weight: 1 }];

​

var b = [{ x: 0, y: 0, value: 1, weight: 1 }, { x: 0, y: 1, value: 3, weight: 1 }];

​

var c = $.extend(true,[],a,b);

console.log(c instanceof Array);

console.log(c);

​

var d = [{ x: 0, y: 0, color: "green", value: 1, weight: 1 }, { x: 0, y: 1, color: "red", value: 3, weight: 1 }];

console.log(d);