Benchmark: JS Object assign vs object new property 2

Tests:

Object assign
const firstObject = { sampleData: 'Hello world' } Object.assign(firstObject, { moreData: 'foo bar' })
Object new property
const firstObject = { sampleData: 'Hello world' } firstObject.moreData = 'foo bar';

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object assign
Object new property

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36

Browser/OS: Chrome 87 on Mac OS X 10.15.2

View result in a separate tab

Test name	Executions per second
Object assign	5491459.5 Ops/sec
Object new property	923432512.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark definition is an object that contains metadata about the test case, but it seems to be incomplete or empty in this example. Typically, a benchmark definition would specify the parameters, inputs, and expected outputs of the test case.

However, looking at the individual test cases, we can infer what's being tested:

* The first test case uses `Object.assign()` to merge two objects.
* The second test case uses the dot notation (`firstObject.moreData = 'foo bar';`) to add a new property to an object.

**Options Compared**

The two options compared are:

1. Using `Object.assign()` to merge two objects.
2. Using the dot notation to add a new property directly to an existing object.

**Pros and Cons of Each Approach**

* **Using `Object.assign()`**: This approach has several pros:
	+ It's widely supported across browsers and versions.
	+ It's more flexible, as it allows for merging multiple objects into one.
	+ However, it can be slower than the dot notation approach due to the overhead of creating a new object and then copying its properties.
* **Using the dot notation**: This approach has several pros:
	+ It's typically faster than `Object.assign()` because it avoids the overhead of creating a new object.
	+ It's more concise and easier to read in some cases.
	However, it also has some cons:
	+ It's not as flexible as `Object.assign()`, as it only allows for adding one property at a time.
	+ It may not be supported by older browsers or versions.

**Library Usage**

In the first test case, the library used is `Object`. The purpose of this library is to provide an object-oriented programming model that allows you to create and manipulate objects in JavaScript.

**Special JS Features/Syntax**

Neither of the two approaches uses any special JavaScript features or syntax. They are both standard JavaScript constructs that have been part of the language for a long time.

**Other Alternatives**

If you want to compare the performance of other ways to merge or add properties to an object, some alternatives could include:

* Using `JSON.parse(JSON.stringify(obj))` to create a deep copy of an object and then modify it.
* Using the spread operator (`{ ...obj, newProp: 'value' }`) to create a new object with merged properties.

However, these approaches are not typically used in production code, as they can be slower and less efficient than the dot notation approach.

Related benchmarks:

JS Object assign vs object new property 2 (version: 0)

Comparing performance of: Object assign vs Object new property

Created: 3 years ago by: Guest

Jump to the latest result

Object assign

Object new property

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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