Benchmark: map over Object (or Record in TS) vs Map

Tests:

Obj / Object.entries()
let obj = {}; for (let i = 0; i < 10000; i++) { obj[i] = i; } let tuples = Object.entries(obj).map(([k, v]) => [k, v]);
Map / spread
let map = new Map(); for (let i = 0; i < 10000; i++) { map.set(i, i); } let tuples = [...map].map(([k, v]) => [k, v]);
Map / Array.from()
let map = new Map(); for (let i = 0; i < 10000; i++) { map.set(i, i); } let tuples = Array.from(map).map(([k, v]) => [k, v]);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Obj / Object.entries()
Map / spread
Map / Array.from()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36

Browser/OS: Chrome 146 on Windows

View result in a separate tab

Test name	Executions per second
Obj / Object.entries()	2975.8 Ops/sec
Map / spread	2676.8 Ops/sec
Map / Array.from()	2598.4 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 its test cases.

**Benchmark Definition JSON**

The provided JSON represents a benchmark definition, which includes:

* `Name`: A unique name for the benchmark.
* `Description`: An optional description of the benchmark (empty in this case).
* `Script Preparation Code` and `Html Preparation Code`: These are empty strings, indicating that no specific code needs to be executed before running the benchmark.

**Individual Test Cases**

There are three test cases:

1. **Obj / Object.entries()**
This test case uses JavaScript's built-in `Object.entries()` method to iterate over an object and convert its key-value pairs into an array of tuples.
2. **Map / spread**
This test case creates a new Map, sets 10,000 key-value pairs, and then converts the map into an array using the spread operator (`[...]`). The resulting array is mapped over to create an array of tuples.
3. **Map / Array.from()**
Similar to the previous test case, this one uses `Array.from()` to convert the map into an array before mapping over it.

**Options Compared**

The three test cases are comparing the performance of different approaches:

* Using `Object.entries()` vs. using a Map and the spread operator (`[...]`).
* Using `Array.from()` vs. using a Map and the spread operator (`[...]`).

**Pros and Cons of Each Approach**

Here's a brief overview of each approach:

1. **Obj / Object.entries()**
	* Pros:
		+ Simple and efficient.
		+ No additional memory allocation is required for the map.
	* Cons:
		+ May not be as performant as using a Map, especially for large datasets.
2. **Map / spread**
	* Pros:
		+ Can take advantage of modern JavaScript engines' ability to optimize map iterations.
		+ Does not require additional memory allocation for the array.
	* Cons:
		+ Requires creating an extra map object and iterating over it twice (once with `Object.entries()` and once again with `[...]`).
3. **Map / Array.from()**
	* Pros:
		+ Similar to the previous approach, but avoids the need to iterate over the map twice.
		+ Still takes advantage of modern JavaScript engines' optimization capabilities.
	* Cons:
		+ Requires creating an extra array object.

**Library and Purpose**

In this benchmark, no external libraries are used. However, JavaScript's built-in `Map` data structure is utilized in all test cases.

**Special JS Feature or Syntax**

None of the test cases use any special JavaScript features or syntax beyond what is commonly available in modern JavaScript implementations.

**Alternatives**

Other approaches to iterate over objects and maps could include:

* Using a custom iterator function.
* Utilizing a library like Lodash's `mapKeys()` or `mapValues()`.
* Implementing a simple loop using indices (e.g., `for (let i = 0; i < obj.length; i++) { ... }`).

Keep in mind that these alternatives might not be as efficient or optimized for modern JavaScript engines, but they can provide alternative perspectives on the problem.

Related benchmarks:

map over Object (or Record in TS) vs Map (version: 0)

Comparing performance of: Obj / Object.entries() vs Map / spread vs Map / Array.from()

Created: 3 years ago by: Registered User

Jump to the latest result

Obj / Object.entries()

Map / spread

Map / Array.from()

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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