why other object change is getting reflected to object it has copied from

Question

In below code I copied item to dummyItem and then changed the description property of dummyItem then why Item's description property is also getting changed. customFilter function gets called for no of items one after another.

Item structure

item = {brand: "test_brand", categorygroup: "Food & Drink", categoryid: 131, categorytext: "Breweries", description:"<b><i>the new description</i><b>", listprice: 123, noofrewards: 14, supplieditems: 1, title: "test_dev"}

customFilter : function(item, args) {
                    if (args.searchString != "" && item.productid.toFixed(2).indexOf(args.searchString.toLowerCase()) == -1 
                                                && item.shortid.toLowerCase().indexOf(args.searchString.toLowerCase()) == -1 
                                                && item.title.toLowerCase().indexOf(args.searchString.toLowerCase()) == -1
                                                && item.brand.toLowerCase().indexOf(args.searchString.toLowerCase()) == -1 
                                                && item.description.toLowerCase().indexOf(args.searchString.toLowerCase()) == -1 
                                                && item.categorytext.toLowerCase(2).indexOf(args.searchString) == -1 
                                                && item.companyid.toFixed(2).indexOf(args.searchString) == -1 
                                                && item.listprice.toFixed(2).indexOf(args.searchString) == -1 
                                                && item.currency.toLowerCase().indexOf(args.searchString.toLowerCase()) == -1) {
                        return false;
                    }
                    var dummyItem = item;
                    dummyItem.description = $('<div></div>').html(item.description).text();
                    $self.filteredData.push(dummyItem);
                    return true;
                },

you didn't copy the object, you just made a new shortcut to it. — dandavis, Nov 20 '14 at 06:13
copy=JSON.parse(JSON.stringify(obj)); (for data props only) if you want to clone object with inherted stuff and methods, it's complicated... — dandavis, Nov 20 '14 at 06:17
Thanks. Also found this var copiedObject = jQuery.extend({},originalObject); — vinayakj, Nov 20 '14 at 06:29
Thanks all for reply. I found the answer here http://stackoverflow.com/questions/728360/most-elegant-way-to-clone-a-javascript-object — vinayakj, Nov 20 '14 at 06:31

score 0 · Answer 1 · 2014-11-20T06:17:43.220

0

You are referring to the same object:

var dummyItem = item;

var src = {
  'a': 45
};
console.log('src, ', src);
var trg = src; // trg is pointing to src
console.log('trg, ', trg);
var cpy = {
  'a': 45
};
console.log('cpy, ', cpy);
console.log('src === trg, ', src === trg); //true
console.log('src === cpy, ', src === cpy); //false

Open console ...

edited Nov 20 '14 at 06:17

answered Nov 20 '14 at 06:12

why other object change is getting reflected to object it has copied from

1 Answers1