Benchmark: Spread vs Object.assign vs Not merging

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign(firstObject, secondObject);
Not merging
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = firstObject

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using Object.assign
Not merging

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.122 Safari/537.36

Browser/OS: Chrome 81 on Mac OS X 10.13.6

View result in a separate tab

Test name	Executions per second
Using the spread operator	18668150.0 Ops/sec
Using Object.assign	4825220.5 Ops/sec
Not merging	761840512.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

The provided benchmark definition json is empty, which means that it doesn't specify what should be tested or compared. However, we can analyze the individual test cases to understand what's being measured.

There are three test cases:

1. "Using the spread operator"
2. "Using Object.assign"
3. "Not merging"

Let's break down each test case and explore what options are compared, pros and cons of those approaches, and other considerations:

**Test Case 1: "Using the spread operator"**

The benchmark definition uses the `...` syntax to create a new object by spreading two existing objects (`firstObject` and `secondObject`). This is known as the "spread operator" or the "rest-spread operator".

Pros:

* The spread operator can be more concise and readable than using `Object.assign()` or other methods.
* It's often faster because it avoids creating an intermediate object.

Cons:

* Some older browsers (e.g., Internet Explorer) might not support this syntax, which could lead to errors.
* Depending on the use case, the performance difference between the spread operator and `Object.assign()` might be negligible.

**Test Case 2: "Using Object.assign()"**

The benchmark definition uses the `Object.assign()` method to merge two objects (`firstObject` and `secondObject`) into a new object (`finalObject`).

Pros:

* `Object.assign()` is widely supported by most modern browsers, making it a reliable choice.
* It's often faster because it avoids creating an intermediate object.

Cons:

* The code might be less concise than using the spread operator.
* Some developers might find `Object.assign()` less readable than other methods.

**Test Case 3: "Not merging"**

This test case simply assigns one object (`firstObject`) to a variable (`finalObject`), without merging or combining any data from another object.

Pros:

* This approach is often the simplest and most straightforward way to assign an object.
* It's usually faster because it avoids creating intermediate objects or performing merges.

Cons:

* The performance difference between this approach and the other two methods might be negligible, depending on the specific use case.
* Depending on the context, not merging objects could lead to unexpected behavior or errors.

Other considerations:

* Memory allocation: Creating an intermediate object using `Object.assign()` or the spread operator requires more memory allocation than simply assigning one object. This could be a concern for developers working with large datasets.
* Browser support: As mentioned earlier, some older browsers might not support the spread operator or require additional libraries to work properly.
* Code readability and maintainability: While brevity is important, code readability and maintainability are equally essential. Using methods like `Object.assign()` or explicit loops can make the code more readable and easier to understand.

Alternatives:

* Other merging methods, such as using a library like Lodash's `merge` function, might be considered.
* Depending on the specific use case, other data structures, like arrays or JSON objects, might be used instead of objects for merging purposes.

Keep in mind that these are just general insights, and the actual performance differences between these approaches will depend on the specific context and requirements.

Related benchmarks:

Spread vs Object.assign vs Not merging (version: 0)

Comparing performance of: Using the spread operator vs Using Object.assign vs Not merging

Created: 4 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

Not merging

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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