Benchmark: Copying objects - MeasureThat.net

Tests:

Spread operator
const a = {aa: 1, bb: 2}; const b = {...a};
JSON
const a = {aa: 1, bb: 2}; const b = JSON.parse(JSON.stringify(a));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread operator
JSON

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

**Overview of the Benchmark**

The provided JSON represents a JavaScript microbenchmark created on MeasureThat.net. The benchmark tests two approaches for copying objects: using the spread operator and using `JSON.parse(JSON.stringify())`. The goal is to determine which approach is faster.

**Benchmark Definition**

The benchmark definition specifies the test cases:

1. **Copying objects**: This test case creates an object `a` with properties `aa` and `bb`, then attempts to create a new object `b` by copying the properties of `a`.
2. **Spread operator**: This test case uses the spread operator (`{...}`) to copy the properties of `a` into `b`.

**Options Compared**

Two options are compared:

1. **Spread operator (`{...}`)**: This approach uses the spread operator to create a new object with the same properties as `a`.
2. **JSON parsing and stringifying (`JSON.parse(JSON.stringify())`)**: This approach converts `a` to a JSON string, parses it back into an object, then creates a new object from the resulting string.

**Pros and Cons**

1. **Spread operator (`{...}`)**:
	* Pros:
		+ Concise and readable syntax.
		+ Fast execution ( O(1) ) since it involves simple property copying.
	* Cons:
		+ Not all browsers support the spread operator, which may lead to compatibility issues.
2. **JSON parsing and stringifying (`JSON.parse(JSON.stringify())`)**:
	* Pros:
		+ Widely supported across most browsers (including older versions).
		+ Can be used for more complex data structures by serializing them as JSON strings.
	* Cons:
		+ Slower execution ( O(n) ) since it involves serialization, parsing, and deserialization.
		+ Requires additional memory to store the temporary JSON string.

**Library and Special JS Features**

None of the test cases use a specific library or special JavaScript features. The spread operator is a built-in feature in modern JavaScript, while `JSON.parse(JSON.stringify())` relies on the built-in `JSON` object.

**Alternative Approaches**

Other alternatives for copying objects could include:

1. **Lodash's `cloneDeep()`**: A utility function that can be used to create deep copies of objects.
2. **Object.assign()**: A method that creates a new object with properties copied from an existing object.
3. **Recursion**: Creating a recursive function to iterate over the object's properties and copy them into a new object.

These alternatives may have varying performance characteristics, compatibility issues, or trade-offs in terms of code readability and maintainability.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/65.0.3325.181 Chrome/65.0.3325.181 Safari/537.36

Browser/OS: Chromium 65 on Ubuntu

View result in a separate tab

Test name	Executions per second
Spread operator	2032055.9 Ops/sec
JSON	424639.5 Ops/sec

Related benchmarks:

Copying objects (version: 0)

Comparing performance of: Spread operator vs JSON

Created: 5 years ago by: Registered User

Jump to the latest result

Spread operator

JSON

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):