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Object.assign vs spred
(version: 0)
Benchmark.js
Foo
Comparing performance of:
Object.assign vs spred
Created:
6 years ago
by:
Guest
Go to the latest result
Tests:
Object.assign
const a = {a: 'foo', b: true, c: 42}; const b = Object.assign({d: '2'}, a);
spred
const a = {a: 'foo', b: true, c: 42}; const b = {...{d: '2'}, ...a};
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
Object.assign
spred
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:152.0) Gecko/20100101 Firefox/152.0
Browser/OS:
Firefox 152 on Mac OS X 10.15
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<iframe src="https://measurethat.net/Embed?id=632923" width="100%" height="500px"></iframe>
Object.assign
30.7M/s
spred
17.2M/s
View exact numbers
Test name
Executions per second
✓
Object.assign
30,748,264 Ops/sec
spred
17,154,770 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the provided benchmark data. **What is being tested?** The website "MeasureThat.net" is testing two different methods for object assignment in JavaScript: `Object.assign()` and spread operator (`...`). The tests are designed to compare the performance of these two approaches on small objects. **Options compared** The main options being compared are: 1. **`Object.assign()`**: This method takes an object as its first argument and an optional source object or value as its second argument. It returns a new object with the properties from the source object, overriding any existing properties in the target object. 2. **Spread operator (`...`)**: This operator allows you to create a new object by spreading the properties of another object. **Pros and cons** Both methods have their trade-offs: * **`Object.assign()`**: + Pros: - More concise syntax - Works with any type of object (arrays, objects, etc.) + Cons: - Can be slower due to the overhead of creating a new object - May not work as expected if the target object is not an object * **Spread operator (`...`)**: + Pros: - Faster and more efficient than `Object.assign()` - Works well with objects, but may require more code for arrays or other types of objects + Cons: - Less concise syntax compared to `Object.assign()` **Library usage** There is no explicit library used in these tests. However, it's worth noting that the spread operator was introduced in ECMAScript 2018, and its support may vary across different browsers and environments. **Special JS features or syntax** The tests use a special JavaScript feature: **rest/spread syntax** (introduced in ECMAScript 2015). This allows you to destructure arrays or objects into individual variables. In the test code, `const b = {...{d: '2'}, ...a};` is using this syntax to create a new object by spreading properties from `a`. **Other alternatives** If you're interested in exploring alternative methods for object assignment, here are some options: 1. **Lodash's `assignIn()` method**: This function is part of the popular Lodash utility library and allows you to assign values to objects while avoiding prototype chain pollution. 2. **Immutable.js**: This library provides a functional programming approach to data manipulation, including methods for creating new objects from existing ones. Keep in mind that these alternatives might not be as concise or straightforward as `Object.assign()` or the spread operator, but they can offer benefits like immutability and predictable behavior in certain scenarios.
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