Benchmark: Object.assign vs direct assignment Markus Test

Script Preparation code:

var data = {};

AخA
 
var data = {};

Tests:

Direct Assignment
for(var i = 0; i < 10000; i++) { data[`prop_${i}`] = true; }
for(var i = 0; i < 10000; i++)
{
data[`prop_${i}`] = true;
}
Object.assign
for(var i = 0; i < 10000; i++) { var propName = `prop_${i}`; Object.assign(data, { [propName]: true }); }
for(var i = 0; i < 10000; i++)
{
var propName = `prop_${i}`;
Object.assign(data, { [propName]: true });
}

test direct assignment

  data = Object.fromEntries(
    Array(10000)
      .fill(true)
      .map((value, index) => [index, value]),
  )

 
  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]), ))
Object.assign(data, Object.fromEntries(
Array(10000)
.fill(true)
.map((value, index) => [index, value]),
))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Experimental features:

Memory measurements supported only in Chrome.
For precise memory measurements Chrome must be launched with --enable-precise-memory-info flag.
More information: Monitoring JavaScript Memory

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:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.45 Safari/537.36

Browser/OS: Chrome 96 on Linux

View result in a separate tab

Test name	Executions per second
Direct Assignment	884.6 Ops/sec
Object.assign	171.5 Ops/sec
test direct assignment	5293.6 Ops/sec
test direct assignment second approach	767.6 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months 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:

Direct Assignment
Object.assign
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_] = 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.

LLMs can make mistakes. Check important info.

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 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: 3 years ago by: Guest

Jump to the latest result

Direct Assignment

Object.assign

test direct assignment

test direct assignment second approach

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):