Benchmark: JavaScript spread operator vs Object.assign performance: empty src1

Tests:

Using the spread operator
const firstObject = {} const secondObject = { sampleData: 'Hello world', moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = {} const secondObject = { sampleData: 'Hello world', moreData: 'foo bar' } const finalObject = Object.assign(firstObject, secondObject);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using Object.assign

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_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.107 Safari/537.36

Browser/OS: Chrome 92 on Mac OS X 10.14.5

View result in a separate tab

Test name	Executions per second
Using the spread operator	14660523.0 Ops/sec
Using Object.assign	5036167.5 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 is being tested.

**Benchmark Definition**

The `Benchmark Definition` JSON represents a microbenchmark that tests the performance of two approaches: using the JavaScript spread operator (`...`) to merge objects, and using the `Object.assign()` method to achieve the same result.

**Options Compared**

Two options are compared:

1. **Using the spread operator**: This approach uses the syntax `{...firstObject, ...secondObject}` to merge two objects, `firstObject` and `secondObject`, into a new object, `finalObject`.
2. **Using Object.assign()**: This approach uses the `Object.assign()` method to explicitly assign properties from one or more source objects to a target object.

**Pros and Cons**

Here are some pros and cons of each approach:

* **Using the spread operator:**
	+ Pros:
		- More concise and readable syntax
		- Can be used with arrays and other iterable types
	+ Cons:
		- May have slower performance compared to `Object.assign()` due to additional overhead (e.g., stringing, method call)
* **Using Object.assign():**
	+ Pros:
		- Generally faster and more efficient than the spread operator approach
		- More predictable behavior in older browsers or environments where spread syntax may not work as expected
	+ Cons:
		- Less concise and less readable syntax compared to the spread operator

**Other Considerations**

When choosing between these two approaches, consider the following factors:

* **Code readability**: If code readability is a top priority, using the spread operator might be a better choice.
* **Performance**: If performance is critical, `Object.assign()` might be a better option, although it may come at the cost of additional syntax complexity.
* **Browser support**: Both approaches work in modern browsers. However, older browsers or environments may not support the spread operator syntax.

**Library and Special JS Features**

There are no libraries used in this benchmark, but JavaScript features like destructuring (not explicitly mentioned here) can be useful when working with objects and arrays.

**Benchmark Preparation Code**

The provided `Script Preparation Code` is empty, which means that the benchmark script does not need to perform any setup or initialization before running the test. The `Html Preparation Code` is also empty, suggesting that no additional HTML setup is required for this benchmark.

**Alternatives**

Other alternatives to using the spread operator and `Object.assign()` include:

* **Using a library like Lodash**: Lodash provides a utility function, `_.merge()`, which can be used to merge objects with a more concise syntax.
* **Using the `Object.keys()` method**: This approach involves iterating over the keys of both objects and assigning values from one object to another.

Keep in mind that these alternatives may have their own trade-offs in terms of performance, readability, and browser support.

Related benchmarks:

JavaScript spread operator vs Object.assign performance: empty src1 (version: 0)

Comparing performance of: Using the spread operator vs Using Object.assign

Created: 3 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

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):