Benchmark: testing assign vs spread

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

Latest run results:

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

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I'll break down what's tested in this benchmark and explain the pros and cons of each approach.

**Benchmark Overview**

The benchmark compares two ways to merge objects in JavaScript: using the spread operator (`...`) and `Object.assign()`. The test cases are identical, with two source objects (`firstObject` and `secondObject`) being merged into a single final object (`finalObject`).

**Options Compared**

1. **Using the Spread Operator (`...`)**: This method uses the syntax `{ ...firstObject, ...secondObject }` to merge the properties of two objects. It's a concise way to create a new object with all the keys from both sources.
2. **Using `Object.assign()`**: This method takes multiple source objects as arguments and returns a new object with all the key-value pairs from each source.

**Pros and Cons**

### Using the Spread Operator (`...`)

Pros:

* Concise syntax, making it easy to read and write
* Creates a new object, which is more efficient than modifying an existing one
* Works well with modern JavaScript versions (ECMAScript 2018 and later)

Cons:

* Not supported in older browsers or environments that don't support ECMAScript 2018
* May not work as expected if the source objects are not objects (e.g., arrays, strings)

### Using `Object.assign()`

Pros:

* Widely supported across different browsers and environments
* Works well with legacy JavaScript versions (pre-ECMAScript 2018)
* Can be used to merge multiple source objects into a single target object

Cons:

* Less concise syntax, making it harder to read and write
* Returns the modified original object, which can be unexpected behavior in some cases

**Library/Function Used**

In this benchmark, `Object.assign()` is used as-is, without any additional libraries or plugins. This function is a built-in part of the JavaScript language.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax used in this benchmark that aren't already explained above. The use of spread operator (`...`) and `Object.assign()` are standard JavaScript constructs.

**Other Alternatives**

If you're interested in alternative ways to merge objects, here are a few options:

1. **Using the `merge` function from `lodash` library**: This library provides a `merge` function that can be used to merge multiple source objects into a single target object.
2. **Using a library like `deepmerge`**: This library provides a way to merge deeply nested objects, handling complex merging scenarios.
3. **Using the `reduce` method**: You can use the `reduce` method to create a new object by merging two or more source objects.

Keep in mind that these alternatives may have different performance characteristics, complexity, and usage scenarios compared to using spread operator (`...`) and `Object.assign()`.

Related benchmarks:

testing assign vs spread (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>

Fastest: N/A

Slowest: N/A

No previous run results

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