Toggle navigation
MeasureThat.net
Create a benchmark
Tools
Feedback
FAQ
Register
Log In
Object.assign vs direct assignment Markus Test
(version: 0)
Comparing performance of:
Direct Assignment vs Object.assign vs test direct assignment vs test direct assignment second approach
Created:
4 years ago
by:
Guest
Jump to the latest result
Script Preparation code:
var data = {};
Tests:
Direct Assignment
for(var i = 0; i < 10000; i++) { data[`prop_${i}`] = true; }
Object.assign
for(var i = 0; i < 10000; i++) { var propName = `prop_${i}`; Object.assign(data, { [propName]: true }); }
test direct assignment
data = Object.fromEntries( Array(10000) .fill(true) .map((value, index) => [index, value]), )
test direct assignment second approach
Object.assign(data, Object.fromEntries( Array(10000) .fill(true) .map((value, index) => [index, value]), ))
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (4)
Previous results
Fork
Test case name
Result
Direct Assignment
Object.assign
test direct assignment
test direct assignment second approach
Fastest:
N/A
Slowest:
N/A
Latest run results:
No previous run results
This benchmark does not have any results yet. Be the first one
to run it!
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 compares three different approaches for assigning values to an object: 1. Direct Assignment 2. `Object.assign` 3. `Object.fromEntries` We'll explore each approach, their pros and cons, and other considerations. **Direct Assignment** Direct assignment involves creating a property on the object using the dot notation (`data[`prop_<i>`] = true;`) for each iteration of the loop. This is a simple and straightforward way to assign values to an object. Pros: * Easy to understand and implement * Efficient, as it only requires accessing the property directly Cons: * Can be slow if the number of properties is large, as the browser needs to resolve the property name for each iteration * May lead to performance issues due to property lookup overhead **`Object.assign`** `Object.assign` is a method that copies the specified values from one or more source objects to a target object. In this benchmark, it's used to assign an array of properties to the `data` object. Pros: * Can be efficient for large datasets, as it allows the browser to use optimized internal data structures * Reduces property lookup overhead compared to direct assignment Cons: * May incur additional overhead due to method invocation and potential type checking * Can lead to slower performance if not implemented correctly (e.g., using `Object.assign` with an array of properties) **`Object.fromEntries`** `Object.fromEntries` is a method that creates a new object from the specified key-value pairs. In this benchmark, it's used as an alternative way to assign values to the `data` object. Pros: * Can be efficient for large datasets, as it allows the browser to use optimized internal data structures * Reduces property lookup overhead compared to direct assignment Cons: * May incur additional overhead due to method invocation and potential type checking * Requires modern browsers that support this method (Chrome 96+) **Library and Special JS Features** None of these approaches rely on any specific libraries or special JavaScript features. They are all standard language constructs. However, it's worth noting that the benchmark uses a technique called "property iteration" to generate an array of properties for assignment. This is a common pattern in JavaScript benchmarks and can affect performance. **Other Alternatives** In addition to these three approaches, there may be other ways to assign values to an object, such as using `Array.prototype.forEach` or creating a custom loop. However, these alternatives are not included in this benchmark. Overall, the benchmark provides a good comparison of three different approaches for assigning values to an object, highlighting the trade-offs between direct assignment, `Object.assign`, and `Object.fromEntries`.
Related benchmarks:
object.assign vs spread to create a copy
Object.assign vs direct copy
Object assign vs empty obj
object spread vs Object.assign
Object.assign vs mutation
Comments
Confirm delete:
Do you really want to delete benchmark?