Benchmark: Object.assign vs. JSON String/Parse deeper object

Tests:

Spread operator
var n = {"foo":"bar","objectinobject":{"obj1":{"hello":"world","foo":"bar"},"arra":[1,2,3,4,5,6],"hello":[{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"}]},"hello":[{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"}]}; while(n.length < 1000) { n = [...n]; }
JSON Parse
var n = {"foo":"bar","objectinobject":{"obj1":{"hello":"world","foo":"bar"},"arra":[1,2,3,4,5,6],"hello":[{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"}]},"hello":[{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"}]}; while(n.length < 1000) { n = JSON.parse(JSON.stringify(n)) }
Object.assign
var n = {"foo":"bar","objectinobject":{"obj1":{"hello":"world","foo":"bar"},"arra":[1,2,3,4,5,6],"hello":[{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"}]},"hello":[{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"},{"hello":"world","foo":"bar"}]}; while(n.length < 1000) { n = Object.assign({}, n); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread operator
JSON Parse
Object.assign

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

Browser/OS: Chrome 124 on Linux

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Test name	Executions per second
Spread operator	2298110.0 Ops/sec
JSON Parse	2397198.2 Ops/sec
Object.assign	2405628.2 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested, compared, and considered.

**Benchmark Overview**

The benchmark compares three different approaches to create and modify an object in JavaScript:

1. **Object.assign()**: Using the `Object.assign()` method to create a new object reference by copying properties from an existing object.
2. **JSON Parse**: Using the `JSON.parse()` function with `JSON.stringify()` to deep clone an object.
3. **Spread Operator** (also known as the rest/spread operator): Using the spread operator (`...`) to create a new array and then assign it to another variable, which is used to create a new object.

**Comparison**

The benchmark measures the performance of each approach when creating a deeply nested object with multiple levels of recursion. The test case uses a complex JSON structure to simulate real-world scenarios where objects are nested and copied.

Here's a brief explanation of each approach:

* **Object.assign()**: This method creates a shallow copy of an object, which means it only copies the top-level properties and does not recursively clone nested objects. In this benchmark, `Object.assign()` is used to create a new object reference by copying properties from the original object.
* **JSON Parse**: This method uses `JSON.stringify()` to serialize the object to a string, which can be then parsed back into a JSON object using `JSON.parse()`. The resulting object is a deep clone of the original object. However, this approach has some overhead due to the serialization and deserialization process.
* **Spread Operator** (Rest/Spread Operator): This method creates a new array by spreading the properties of an object, which can then be assigned to another variable to create a new object reference. The spread operator is used to create a new object by recursively cloning nested objects.

**Pros and Cons**

Here are some pros and cons for each approach:

* **Object.assign()**: Pros: fast, lightweight, easy to use. Cons: creates a shallow copy, may not work well with recursive objects.
* **JSON Parse**: Pros: creates a deep clone, reliable. Cons: can be slow due to serialization and deserialization overhead, may require additional libraries for compatibility.
* **Spread Operator** (Rest/Spread Operator): Pros: fast, lightweight, easy to use. Cons: may not work well with very large or complex objects, can lead to stack overflow errors if used recursively.

**Library Considerations**

The test case uses the `JSON` library implicitly through `JSON.stringify()` and `JSON.parse()`. The `Object.assign()` method is a native JavaScript function, so no additional libraries are required.

**Special JavaScript Features**

There are no special JavaScript features or syntaxes being tested in this benchmark. However, the spread operator is a relatively recent feature that was introduced in ECMAScript 2015 (ES6).

**Alternatives**

Other alternatives to these approaches include:

* Using a library like Lodash or Ramda for deep cloning and manipulation of objects.
* Implementing custom recursive functions for object copying and creation.
* Using native JavaScript methods like `Object.create()` and `Object.assign()` in combination.

Overall, the benchmark highlights the trade-offs between different approaches to creating and modifying objects in JavaScript. The choice of approach depends on the specific use case, performance requirements, and personal preference.

Related benchmarks:

Object.assign vs. JSON String/Parse deeper object (version: 0)

Creating a "new" object reference every time

Comparing performance of: Spread operator vs JSON Parse vs Object.assign

Created: 5 years ago by: Guest

Jump to the latest result

Spread operator

JSON Parse

Object.assign

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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