Benchmark: Deep copy comparison

Deep copy comparison (version: 0)

Benchmarks for StackOverflow question on deep copy techniques https://stackoverflow.com/questions/7486085/copy-array-by-value/23536726#23536726

Comparing performance of: spread ... vs slice() vs splice(0) vs concat() vs JSON.parse(JSON.stringify()) vs Custom function vs Lodash.cloneDeep() vs jQuery.extend(true)

Created: 4 years ago by: Guest

Jump to the latest result

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js" integrity="sha512-894YE6QWD5I59HgZOGReFYm4dnWc1Qt5NtvYSaNcOP+u1T9qYdvdihz0PPSiiqn/+/3e7Jo4EaG7TubfWGUrMQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js" integrity="sha512-WFN04846sdKMIP5LKNphMaWzU7YpMyCU245etK3g/2ARYbPK9Ub18eG+ljU96qKRCWh+quCY7yefSmlkQw1ANQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>

Tests:

spread ...
const arr1 = [ true, 1, "true", [], {}, function () {} ]; // Deep copies: true, 1, "true" // Shallow copies: [], {}, function () {} const arr2 = [ ...arr1 ];
slice()
const arr1 = [ true, 1, "true", [], {}, function () {} ]; // Deep copies: true, 1, "true" // Shallow copies: [], {}, function () {} const arr2 = arr1.slice();
splice(0)
const arr1 = [ true, 1, "true", [], {}, function () {} ]; // Deep copies: true, 1, "true" // Shallow copies: [], {}, function () {} const arr2 = arr1.splice(0);
concat()
const arr1 = [ true, 1, "true", [], {}, function () {} ]; // Deep copies: true, 1, "true" // Shallow copies: [], {}, function () {} const arr2 = arr1.concat();
JSON.parse(JSON.stringify())
const arr1 = [ true, 1, "true", [], {}, function () {} ]; // Deep copies: true, 1, "true", [], {} // Shallow copies: function () {} const arr2 = JSON.parse(JSON.stringify(arr1));
Custom function
function copy(aObject) { // Prevent undefined objects // if (!aObject) return aObject; let bObject = Array.isArray(aObject) ? [] : {}; let value; for (const key in aObject) { // Prevent self-references to parent object // if (Object.is(aObject[key], aObject)) continue; value = aObject[key]; bObject[key] = (typeof value === "object") ? copy(value) : value; } return bObject; } const arr1 = [ true, 1, "true", [], {}, function () {} ]; // Deep copies: true, 1, "true", [], {}, function () {} const arr2 = copy(arr1);
Lodash.cloneDeep()
const arr1 = [ true, 1, "true", [], {}, function () {} ]; // Deep copies: true, 1, "true", [], {}, function () {} const arr2 = _.cloneDeep(arr1);
jQuery.extend(true)
const arr1 = [ true, 1, "true", [], {}, function () {} ]; // Deep copies: true, 1, "true", [], {}, function () {} const arr2 = jQuery.extend(true, [], arr1);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread ...
slice()
splice(0)
concat()
JSON.parse(JSON.stringify())
Custom function
Lodash.cloneDeep()
jQuery.extend(true)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:147.0) Gecko/20100101 Firefox/147.0

Browser/OS: Firefox 147 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
spread ...	22722314.0 Ops/sec
slice()	39743968.0 Ops/sec
splice(0)	22542942.0 Ops/sec
concat()	32977158.0 Ops/sec
JSON.parse(JSON.stringify())	2681431.2 Ops/sec
Custom function	3413516.5 Ops/sec
Lodash.cloneDeep()	2055885.1 Ops/sec
jQuery.extend(true)	2144566.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

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