Benchmark: Merge list of objects

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var allObjs = [{ a: 'oh', b: 'my' }, { c: 'goddess' }, {d: '.'}, {a: 'you\'re', b: 'out'}]

Tests:

merge
var c = _.merge({}, ...allObjs);
object.assign
var c = allObjs.reduce(function(p, c){ return Object.assign(p, c); }, {})
Assign
var c = _.assign({}, ...allObjs);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
merge
object.assign
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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**Overview of the Benchmark**

The provided JSON represents a JavaScript benchmarking test created using MeasureThat.net. The test aims to compare the performance of three different approaches for merging multiple objects: `_.merge`, `object.assign`, and `lodash.assign`.

**Benchmark Definition**

The benchmark definition is represented by the `Script Preparation Code` and `Html Preparation Code` fields in the JSON. These codes are used to set up the environment for the benchmark:

* `Script Preparation Code`: This code defines an array of objects (`allObjs`) that will be merged.
* `Html Preparation Code`: This code includes a reference to the Lodash library, which provides the `_merge`, `_assign` functions.

**Individual Test Cases**

There are three test cases in this benchmark:

1. **`merge`**: This test case uses the `_.merge` function from Lodash to merge all objects in the `allObjs` array.
2. **`object.assign`**: This test case uses the built-in `Object.assign` method to merge all objects in the `allObjs` array.
3. **`Assign`**: This test case uses the `_assign` function from Lodash to merge all objects in the `allObjs` array.

**Comparison of Approaches**

Here's a brief overview of each approach:

* **`_.merge` and `_assign`**: These functions from Lodash recursively merge objects based on their keys. They are optimized for performance and provide a convenient way to handle object merges.
* **`object.assign`**: This built-in method creates a new object by copying all enumerable own properties from one or more source objects. It is a simple and efficient way to perform object merges, but may not be as efficient as the Lodash functions.

**Pros and Cons**

Here are some pros and cons of each approach:

* **`.merge` and `_assign`**:
	+ Pros: Optimized for performance, easy to use, and provides a convenient way to handle complex object merges.
	+ Cons: Requires an external library (Lodash), may have additional dependencies.
* **`object.assign`**:
	+ Pros: Built-in method, simple to use, and has minimal dependencies.
	+ Cons: May not be as efficient as the Lodash functions, can lead to shallow copies if not used carefully.

**Other Considerations**

When choosing an approach for merging objects in JavaScript, consider the following:

* **Deep vs Shallow Merges**: If you need to merge objects deeply (e.g., nested objects), one of the Lodash functions may be a better choice. For shallow merges, `object.assign` can be sufficient.
* **Performance**: If performance is critical, use optimized methods like `_merge` or `_assign`.
* **Readability and Maintainability**: Choose an approach that is easy to understand and maintain.

**Alternatives**

If you prefer not to use Lodash, you can implement your own object merge functions. Here's a simple example using the spread operator (`{ ... }`):

```javascript
function mergeObjects(obj1, obj2) {
  return { ...obj1, ...obj2 };
}
```

Another option is to use the `Object.assign()` method with an empty object:

```javascript
function mergeObjects(obj1, obj2) {
  return Object.assign({}, obj1, obj2);
}
```

Keep in mind that these implementations may not be as efficient or convenient as the Lodash functions.

Related benchmarks:

Merge list of objects (version: 0)

Comparing performance of: merge vs object.assign vs Assign

Created: 7 years ago by: Registered User

Jump to the latest result

merge

object.assign

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):