Benchmark: JavaScript spread operator vs Object.assign performance 0109

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);

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

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

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**Benchmark Definition**

The benchmark measures the performance of two ways to merge objects: using the spread operator (`...`) and `Object.assign`. The test creates two objects, `firstObject` and `secondObject`, each with some sample data. Then, it attempts to create a new object, `finalObject`, by merging these two objects.

**Options Compared**

There are two options being compared:

1. **Using the spread operator (`...`)**: This approach uses the syntax `const finalObject = { ...firstObject, ...secondObject };` to merge the two objects.
2. **Using `Object.assign()`**: This approach uses the function `Object.assign({}, firstObject, secondObject);` to create a new object by merging the two input objects.

**Pros and Cons**

Here are some pros and cons of each approach:

* **Using the spread operator (`...`):**
	+ Pros:
		- Concise and readable syntax
		- Works well with modern JavaScript engines that support it
		- Can be faster because it avoids creating intermediate objects
	+ Cons:
		- May not work as expected in older browsers or environments that don't support the spread operator
		- Can lead to unexpected behavior if not used carefully (e.g., merging arrays with `...`)
* **Using `Object.assign()`**:
	+ Pros:
		- Widely supported across all browsers and environments
		- Allows for more control over the resulting object (e.g., using the `merge` option)
		- Can be safer when working with legacy code or complex data structures
	+ Cons:
		- Less readable syntax compared to the spread operator
		- May create intermediate objects, which can lead to performance overhead

**Library**

There is no explicit library being used in these benchmarks. However, it's worth noting that `Object.assign()` is a built-in method on the `Object` prototype in JavaScript.

**Special JS Features or Syntax**

None of the provided benchmarks use any special JavaScript features or syntax.

**Other Considerations**

When choosing between these two approaches, consider the following:

* If you need to work with modern browsers and can take advantage of the spread operator's conciseness, it might be a good choice. However, if you need to support older environments or want more control over the merging process, `Object.assign()` is still a reliable option.
* Be mindful of potential performance differences, as the spread operator might lead to better results in some cases.

**Alternatives**

Some alternative approaches for merging objects include:

1. **Using `Object.create()`**: This method creates a new object with a specified prototype and then merges properties from another object using the `Object.assign()` method.
2. **Using a custom function**: You can create a custom function to merge objects, taking advantage of any performance optimizations or features specific to your use case.
3. **Using a library like Lodash**: Libraries like Lodash provide optimized functions for merging objects, which might be worth considering if you need more control over the process.

Keep in mind that these alternatives may have different pros and cons compared to using the spread operator or `Object.assign()`.

Related benchmarks:

JavaScript spread operator vs Object.assign performance 0109 (version: 0)

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

Created: 4 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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