Benchmark: Deep clone JS Object

Tests:

structuredClone
const anObj = { k1: "hello", k2: { k3: "world", k4: [ { k5: "I", k6: "doing", k7: [[true, null]] } ] }, k8: [2023, { k9: "what" }] } const newObj = structuredClone(anObj)
JSON
const anObj = { k1: "hello", k2: { k3: "world", k4: [ { k5: "I", k6: "doing", k7: [[true, null]] } ] }, k8: [2023, { k9: "what" }] } const newObj = JSON.parse(JSON.stringify(anObj))

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Suite status: <idle, ready to run>

Previous results

Test case name	Result
structuredClone
JSON

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

**Benchmark Overview**

The benchmark is designed to measure the performance of two different methods for deep cloning JavaScript objects: `JSON` and `structuredClone`. Deep cloning means creating a new, independent copy of an object that includes all its properties and nested structures.

**Options Being Compared**

There are two options being compared:

1. **JSON**: This method uses the `JSON.parse(JSON.stringify(anObj))` syntax to create a deep clone of the input object `anObj`. The idea is to parse the JSON representation of `anObj`, then use the `JSON.parse()` function again with the original object as the input.
2. **structuredClone**: This method uses the `structuredClone()` function, which was introduced in ECMAScript 2020 (ES10) as a built-in function for creating deep clones of objects.

**Pros and Cons**

* **JSON**: While simple to use, this method can be slow due to the overhead of parsing JSON multiple times. It also doesn't handle certain edge cases, such as arrays with `undefined` values or circular references.
* **structuredClone**: This method is specifically designed for deep cloning objects and is more efficient than the `JSON` approach. However, it may not work in older browsers that don't support this function.

**Other Considerations**

* The benchmark uses a simple JavaScript object as input, with one level of nesting. In real-world scenarios, you might need to handle more complex objects with multiple levels of nesting.
* The benchmark doesn't consider issues like memory allocation or garbage collection, which can affect performance in certain situations.
* The `structuredClone()` function is a relatively new addition to JavaScript, and its adoption may not be uniform across all browsers.

**Library or Special JS Feature Used**

The benchmark uses the `JSON.parse(JSON.stringify(anObj))` syntax, which relies on the `JSON.stringify()` method. This method has been available in JavaScript since ES5.

**Special JS Feature or Syntax (if applicable)**

There is no special JavaScript feature or syntax used in this benchmark. The focus is solely on measuring the performance of two different cloning methods.

**Alternatives**

If you need to clone a JavaScript object, other alternatives include:

1. **Lodash.cloneDeep()**: A popular utility library that provides a `cloneDeep()` function for deep cloning objects.
2. **Underscore.js.clone()**: Another utility library that provides a `clone()` function for deep cloning objects.
3. **Manual implementation**: You can implement your own deep cloning algorithm using recursion or iteration, which might be more efficient than the built-in methods.

Keep in mind that the performance of these alternatives may vary depending on the specific use case and browser support.

Related benchmarks:

Deep clone JS Object (version: 0)

Deep clone JS Object

Comparing performance of: structuredClone vs JSON

Created: 3 years ago by: Guest

Jump to the latest result

structuredClone

JSON

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):