use object assign to copy without reference code example
Example 1: copy object javascript
var x = {myProp: "value"};
var y = Object.assign({}, x);
Example 2: clone an object javascript
//returns a copy of the object
function clone(obj) {
if (null == obj || "object" != typeof obj) return obj;
var copy = obj.constructor();
for (var attr in obj) {
if (obj.hasOwnProperty(attr)) copy[attr] = obj[attr];
}
return copy;
}