Toggle navigation
MeasureThat
.net
Create a benchmark
Tools
Feedback
FAQ
Register
Log In
lodash merge vs object.assign vs spread overwriting one property
(version: 0)
Comparing performance of:
lodash merge vs object.assign vs spread
Created:
6 years ago
by:
Guest
Go to the latest result
HTML Preparation code:
<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>
Tests:
lodash merge
var a = { a: 'oh', b: 'my' }; var c = _.merge({a:true}, a);
object.assign
var a = { a: 'oh', b: 'my' }; var c = Object.assign({a:true}, a);
spread
var a = { a: 'oh', b: 'my' }; var c = { a:true, ...a };
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (3)
Previous results
Fork
Test case name
Result
lodash merge
object.assign
spread
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
2 years ago
)
User agent:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36
Browser/OS:
Chrome 119 on Mac OS X 10.15.7
View result in a separate tab
Embed
Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=494001" width="100%" height="500px"></iframe>
spread
40.9M/s
object.assign
12.6M/s
lodash merge
6.2M/s
View exact numbers
Test name
Executions per second
✓
spread
40,911,312 Ops/sec
object.assign
12,627,836 Ops/sec
lodash merge
6,155,501 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the provided benchmark and explain what is being tested. **Benchmark Overview** The benchmark measures the performance of three different approaches to merge objects in JavaScript: `_.merge` from Lodash, `Object.assign`, and spread operator (`...`). The test creates two objects, `a` and `b`, with some common properties. Then, it defines a new object `c` using each of these methods. **Options Compared** The benchmark compares the performance of three approaches: 1. **_.merge` from Lodash**: This method merges two objects into one, overwriting any common properties. 2. **`Object.assign`**: This method copies all enumerable own properties from one or more source objects to a target object. 3. **Spread operator (`...`) with overwrite**: This method uses the spread operator to create a new object and then assigns the `a` object to it, overwriting any common properties. **Pros and Cons** * **_.merge` from Lodash:** + Pros: - Simple and concise syntax - Can handle nested objects + Cons: - May be slower than other approaches due to overhead of function call and argument validation * `Object.assign`:** + Pros: - Fast and efficient - Supports shallow copying of arrays and functions + Cons: - Less readable syntax for complex merge scenarios - Does not handle nested objects well * Spread operator (`...` with overwrite):** + Pros: - Modern and concise syntax - Can handle nested objects (in modern browsers that support it) + Cons: - May not work in older browsers or environments without object spread syntax - Can be less readable for complex merge scenarios **Library** The benchmark uses the Lodash library, which provides a `merge` function to merge two objects into one. This library is widely used and well-regarded in the JavaScript community. **Special JS Feature/Syntax** * The benchmark uses the spread operator (`...`) with overwrite syntax, which was introduced in ECMAScript 2018 (ES2018) as part of the Object Spread Operator (Spread Syntax) feature. This syntax allows you to create a new object and then assign an existing object to it using the spread operator. **Other Alternatives** If you're interested in exploring other alternatives for merging objects, here are some options: * **`Object.assign()` with nested objects**: You can use `Object.assign()` recursively by calling it on each property of the source object. * **Merges libraries like `merge-deep` or `lodash.merge Deep`**: These libraries provide more advanced merge functionality that handles nested objects and other edge cases. * **Custom implementation using `for...in` loop**: You can write a custom implementation using a `for...in` loop to iterate over the properties of both objects and assign values to the new object.
Related benchmarks
lodash merge vs object.assign vs spread new obj
lodash.assign vs object.assign vs spread
lodash assign vs object.assign vs spread operator - variable and constant
Comments
Confirm delete:
Do you really want to delete benchmark?