Benchmark: Lodash clone vs Object.assign

HTML Preparation code:

<script src='https://cdn.jsdelivr.net/npm/object-assign-polyfill@0.1.0/index.min.js'></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var MyObject = {
  description: 'Creates a deep copy of source, which should be an object or an array.',
  myNumber: 123456789,
  myBoolean: true,
  jayson: {
    stringify: 'JSON.stringify() method converts a JavaScript value to a JSON string....',
    parse: 'JSON.parse() method parses a JSON string...'
  }
};

var myCopy = null;

Tests:

Lodash cloneDeep
myCopy = _.clone(MyObject);
Json clone
myCopy = Object.assign({}, MyObject)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Lodash cloneDeep
Json clone

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.

Let's break down the provided benchmark and explain what is being tested.

**What is being tested?**

The benchmark measures the performance of two approaches to create a deep copy of an object:

1. **Lodash cloneDeep**: This method uses the `cloneDeep` function from the Lodash library, which recursively clones the entire object.
2. **Object.assign**: This method creates a new object and copies the properties from the original object into it.

**Options compared**

The two options being compared are:

*   Recursion vs Iteration: Lodash cloneDeep uses recursion to create a deep copy of the object, while Object.assign iterates over the properties of the original object to create a new one.
*   Library usage: Lodash cloneDeep relies on the Lodash library for its implementation, whereas Object.assign is a native JavaScript function.

**Pros and Cons**

*   **Lodash cloneDeep**: Pros:
    *   Easy to implement and use
    *   Handles nested objects and arrays correctly
    *   Supports many other functions from Lodash
*   Cons:
    *   Additional overhead due to the need for the Lodash library
    *   Might be slower than Object.assign due to the extra function call
*   **Object.assign**: Pros:
    *   Fastest way to create a shallow copy of an object
    *   Native JavaScript function, no additional overhead
*   Cons:
    *   Only creates a shallow copy (first-level only)
    *   May not handle nested objects and arrays correctly

**Library usage**

The Lodash library is used for the `cloneDeep` function. It provides a convenient way to create deep copies of objects, as well as many other utility functions.

**Special JavaScript feature or syntax**

There is no specific special JavaScript feature or syntax being tested in this benchmark. Both approaches are standard JavaScript methods.

**Other alternatives**

If you need to create a deep copy of an object without using Lodash, you can implement your own recursive function:

```javascript
function cloneDeep(obj) {
  if (typeof obj !== 'object' || obj === null) return obj;

const clone = Array.isArray(obj) ? [] : {};

for (const key in obj) {
    clone[key] = cloneDeep(obj[key]);
  }

return clone;
}
```

Alternatively, you can use a library like `lodash` or `json-stringify-safe` to create deep copies of objects.

**Benchmark preparation code**

The script preparation code defines two objects:

*   `MyObject`: The original object with nested properties
*   `myCopy`: The variable that will store the cloned copy of `MyObject`

The Html Preparation Code includes external scripts for Lodash and Object-assign-polyfill, as they are required for this benchmark.

**Individual test cases**

There are two test cases:

1.  **Lodash cloneDeep**: Creates a deep copy of `MyObject` using the `cloneDeep` function from Lodash.
2.  **Json clone**: Creates a shallow copy of `MyObject` using the `Object.assign` method.

These test cases measure the performance of each approach under different conditions, including various browsers and devices.

Related benchmarks:

Lodash clone vs Object.assign (version: 0)

Comparing performance of: Lodash cloneDeep vs Json clone

Created: 5 years ago by: Registered User

Jump to the latest result

Lodash cloneDeep

Json clone

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):