Benchmark: Lodash cloneDeep vs merge vs ES6 object spread vs ES6 Object.assign

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.19/lodash.min.js'></script>

Script Preparation code:

var o = {
    a: {
        b: 1,
        c: 2,
        d: 3,
        j: {
            k: [1, 2, 3],
            l: [4, 5, 6]
        },
    },
    e: [1, 2, 3, 4, 5, 6],
    f: 1,
    g: {
        h: 1,
    }
}

Tests:

lodash clone deep
const a = _.cloneDeep(o)
Object spread
const a = { ...o }
Assign
const a = Object.assign({}, o)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash clone deep
Object spread
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):

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmarking test case on the MeasureThat.net website. The benchmark compares the performance of three approaches to create a deep copy of an object: Lodash's `cloneDeep`, Object spread operator (`{ ...o }`), and `Object.assign()`.

**Library Used**

In this benchmark, the library used is Lodash, specifically its `cloneDeep` function. Lodash is a popular JavaScript utility library that provides various helper functions for tasks such as array manipulation, object manipulation, and more.

The purpose of using Lodash's `cloneDeep` function in this benchmark is to create a deep copy of an object, which involves recursively creating new objects for all nested properties.

**Special JS Features or Syntax**

In this benchmark, the following special JavaScript features or syntax are used:

* **Object spread operator**: This is a modern JavaScript feature introduced in ECMAScript 2018. It allows you to create a new object by spreading an existing object's properties into it using the `{ ... }` syntax.
* **Object.assign()**: This is another built-in JavaScript method that creates a new object by copying all enumerable own properties from one or more source objects into a target object.

**Approaches Compared**

The three approaches compared in this benchmark are:

1. **Lodash cloneDeep**: Uses Lodash's `cloneDeep` function to create a deep copy of the input object.
2. **Object spread operator ( {...} )**: Creates a new object by spreading the properties of the original object using the `{ ... }` syntax.
3. **Object.assign()**: Creates a new object by copying all enumerable own properties from the original object into it.

**Pros and Cons of Each Approach**

Here are some pros and cons of each approach:

* **Lodash cloneDeep**:
	+ Pros: Provides a simple way to create a deep copy of an object, handles complex nested objects recursively.
	+ Cons: Requires Lodash library, can be slower than other approaches for very large inputs.
* **Object spread operator ( {...} )**:
	+ Pros: Fast and lightweight, does not require any additional libraries.
	+ Cons: Only creates a shallow copy of the object, may not handle complex nested objects correctly.
* **Object.assign()**:
	+ Pros: Simple to use, handles simple cases well.
	+ Cons: Can be slower than other approaches for very large inputs, only creates a shallow copy of the object.

**Other Considerations**

When choosing an approach for creating a deep copy of an object in JavaScript, consider factors such as:

* Performance: Object spread operator and `Object.assign()` are generally faster than Lodash's `cloneDeep`.
* Complexity: If you need to handle complex nested objects with multiple levels of recursion, Lodash's `cloneDeep` may be the best choice.
* Library dependencies: If you want to avoid using an additional library like Lodash, consider using the object spread operator or `Object.assign()`.

**Alternative Approaches**

If you're looking for alternative approaches to create a deep copy of an object in JavaScript, consider:

* **JSON.parse(JSON.stringify(obj))**: This approach creates a new object by recursively copying all properties from the original object.
* **Array.prototype.slice.call(obj) + Array.prototype.reduce()**: This approach creates a new array and then uses `reduce()` to merge it with the original object.

Keep in mind that these alternatives may have different performance characteristics and complexity compared to the approaches used in this benchmark.

Related benchmarks:

Lodash cloneDeep vs merge vs ES6 object spread vs ES6 Object.assign (version: 0)

Comparing performance of: lodash clone deep vs Object spread vs Assign

Created: 2 years ago by: Guest

Jump to the latest result

lodash clone deep

Object spread

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):