Benchmark: Map clone vs Object clone

Tests:

Map Clone
const map = new Map(); const object = {}; for (i = 0; i < 30; i++) { object[`${i}_key`, i]; map.set(`${i}_key`, i); } const newMap = new Map(map.entries())
Object Clone
const map = new Map(); const object = {}; for (i = 0; i < 30; i++) { object[`${i}_key`, i]; map.set(`${i}_key`, i); } const newObject = {...object}

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map Clone
Object Clone

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.97 Safari/537.36

Browser/OS: Chrome 83 on Mac OS X 10.15.5

View result in a separate tab

Test name	Executions per second
Map Clone	219615.7 Ops/sec
Object Clone	379336.2 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

**What is being tested?**

The provided JSON represents two test cases for measuring the performance of creating and cloning objects in JavaScript. The first test case, "Map Clone", tests the creation of a new Map instance from an existing Map object using the `entries()` method. The second test case, "Object Clone", tests the creation of a new object by spreading an existing object using the `{...}` syntax.

**Options being compared:**

The two options being compared are:

1. **Using the `Map` constructor to create a new Map instance from an existing Map object**: This method creates a shallow copy of the map, where only the key-value pairs are copied.
2. **Spreading an existing object using the `{...}` syntax**: This method creates a deep copy of the object, where all properties and their values are recursively copied.

**Pros and Cons:**

* **Using the `Map` constructor**:
	+ Pros:
		- Faster performance since only the key-value pairs need to be copied.
		- Less memory usage since the map's internal data structure is not recreated.
	+ Cons:
		- May not work correctly if the Map object contains complex values, such as other Maps or objects with cyclic references.
		- Does not preserve the map's prototype chain.
* **Spreading an existing object using `{...}`**:
	+ Pros:
		- Works correctly for most objects, including those with complex values and prototype chains.
		- Preserves all properties of the original object, including their values and metadata.
	+ Cons:
		- Can be slower performance since all properties need to be recursively copied.
		- May use more memory depending on the size of the object.

**Library usage:**

In this benchmark, no libraries are explicitly used. However, it's worth noting that some JavaScript engines may have built-in optimizations or features that can affect the performance of these operations.

**Special JS feature:**

There is no specific special JavaScript feature being tested in this benchmark. The focus is on measuring the performance of basic object creation and cloning techniques.

**Other alternatives:**

If you need to measure the performance of other object creation or cloning techniques, some alternatives might include:

* Using `JSON.parse(JSON.stringify(obj))` to create a deep copy of an object.
* Using a library like Lodash's `cloneDeep()` function to create a deep copy of an object.
* Using a framework like React or Angular that provides built-in support for shallow and deep cloning of objects.

Keep in mind that the best approach will depend on your specific use case and requirements.

Related benchmarks:

Map clone vs Object clone (version: 0)

Comparing performance of: Map Clone vs Object Clone

Created: 4 years ago by: Guest

Jump to the latest result

Map Clone

Object Clone

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):