Benchmark: JSON.parse(JSON.stringify())1 vs structuredClone

Script Preparation code:

function createBigObject(depth) {
    const obj = {};
    for (let i = 0; i < 5000; i++) {
        obj[i + Math.floor(Math.random() * 10000)] = {
            [Math.random() * 10000]: Math.random() * 10000,
        };
    }
    return obj;
}
var bigObj = createBigObject()
var clone;

Tests:

JSON
clone = JSON.parse(JSON.stringify(bigObj))
structuredClone
clone = structuredClone(bigObj)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
JSON
structuredClone

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36

Browser/OS: Chrome 123 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
JSON	408.6 Ops/sec
structuredClone	454.1 Ops/sec

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's being tested, compared, and considered.

**Benchmark Overview**

The benchmark is designed to compare the performance of two approaches: `JSON.parse(JSON.stringify())` and `structuredClone()` on a large object cloning. The benchmark aims to determine which approach is faster and more efficient.

**Test Cases**

There are two test cases:

1. **JSON**: The first test case uses the classic way of cloning an object using `JSON.parse(JSON.stringify())`. This method creates a deep copy of the original object by recursively traversing its properties.
2. **structuredClone():** The second test case uses the `structuredClone()` function, which is introduced in ECMAScript 2020 as a new way to create a shallow or deep clone of an object.

**Comparison**

The benchmark compares the performance of these two approaches on a large object cloning:

```javascript
const bigObj = createBigObject();
var clone;
clone = JSON.parse(JSON.stringify(bigObj)); // Test Case: JSON
```

```javascript
structuredClone(bigObj); // Test Case: structuredClone
```

**Options Compared**

The benchmark compares the following options:

1. **Deep Cloning**: `JSON.parse(JSON.stringify())` creates a deep copy of the original object, which can be slower and more memory-intensive.
2. **Shallow Cloning**: `structuredClone()` creates a shallow clone of the original object, which is faster but may not preserve all properties or values.

**Pros and Cons**

1. **Deep Cloning (JSON.parse(JSON.stringify()))**:
	* Pros: Preserves all properties and values, can be useful for complex objects.
	* Cons: Slower, more memory-intensive due to the recursive traversal of properties.
2. **Shallow Cloning (structuredClone())**:
	* Pros: Faster, less memory-intensive since it doesn't traverse property values recursively.
	* Cons: May not preserve all properties or values.

**Library and Purpose**

The `structuredClone()` function is part of the ECMAScript specification and is designed to provide a more efficient way of cloning objects. Its primary purpose is to avoid the overhead of recursive traversal for shallow copies, while still preserving most properties and values.

**Special JS Feature or Syntax**

`structuredClone()` is a relatively new feature introduced in ECMAScript 2020, so it's not surprising that MeasureThat.net includes it as an option. This highlights the importance of keeping up-to-date with the latest JavaScript features and best practices.

**Other Alternatives**

If you need to clone objects frequently, you might want to consider other options:

1. **Lodash's `cloneDeep()`**: A popular utility library function that creates a deep copy of an object.
2. **Purestella's `createCopy()`**: Another utility library function that creates a shallow or deep copy of an object.

Keep in mind that these alternatives might not be as optimized or efficient as the `structuredClone()` method, but they can provide a convenient solution when working with JavaScript objects.

Related benchmarks:

JSON.parse(JSON.stringify())1 vs structuredClone (version: 0)

Comparing performance of: JSON vs structuredClone

Created: 2 years ago by: Registered User

Jump to the latest result

JSON

structuredClone

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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