copy item js code example
Example 1: javascript copy an object without reference
var obj = {a: 25, b: 50, c: 75};
var A = Object.create(obj);
var B = Object.create(obj);
A.a = 30;
B.a = 40;
alert(obj.a + " " + A.a + " " + B.a); // 25 30 40
Example 2: copy object javascript
var x = {key: 'value'}
var y = JSON.parse(JSON.stringify(x))
//this method actually creates a reference-free version of the object, unlike the other methods
//If you do not use Dates, functions, undefined, regExp or Infinity within your object