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]);

Historical Performance Data aggregated from 134 community runs

Desktop Results:

Chrome 100 runs

Obj / Object.entries()

3K/s

Map / Array.from()

2K/s

Map / spread

2K/s

Fastest: Obj / Object.entries() (1.6x faster)

View exact numbers

✓ Obj / Object.entries(): 2,940 ops/sec
• Map / Array.from(): 1,985 ops/sec
• Map / spread: 1,839 ops/sec

Firefox 20 runs

Obj / Object.entries()

2K/s

Map / spread

2K/s

Map / Array.from()

2K/s

Fastest: Obj / Object.entries() (1.4x faster)

View exact numbers

✓ Obj / Object.entries(): 2,485 ops/sec
• Map / spread: 1,733 ops/sec
• Map / Array.from(): 1,728 ops/sec

Mobile Results:

Chrome 9 runs

Obj / Object.entries()

1K/s

Map / Array.from()

848/s

Map / spread

742/s

Fastest: Obj / Object.entries() (1.6x faster)

View exact numbers

✓ Obj / Object.entries(): 1,157 ops/sec
• Map / Array.from(): 848 ops/sec
• Map / spread: 742 ops/sec

Firefox 5 runs

Obj / Object.entries()

1K/s

Map / Array.from()

702/s

Map / spread

512/s

Fastest: Obj / Object.entries() (2.0x faster)

View exact numbers

✓ Obj / Object.entries(): 1,034 ops/sec
• Map / Array.from(): 702 ops/sec
• Map / spread: 512 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

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 (X11; Linux x86_64; rv:151.0) Gecko/20100101 Firefox/151.0

Browser/OS: Firefox 151 on Linux

View result in a separate tab

Obj / Object.entries()

2K/s

Map / spread

1K/s

Map / Array.from()

1K/s

View exact numbers

Test name	Executions per second
✓ Obj / Object.entries()	1,725 Ops/sec
Map / spread	1,260 Ops/sec
Map / Array.from()	1,256 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.

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

Go to the latest result

Obj / Object.entries()

Map / spread

Map / Array.from()

Historical Performance Data aggregated from 134 community runs

Desktop Results:

Chrome 100 runs

Firefox 20 runs

Mobile Results:

Chrome 9 runs

Firefox 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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

Go to the latest result

Obj / Object.entries()

Map / spread

Map / Array.from()

Historical Performance Data aggregated from 134 community runs

Desktop Results:

Chrome 100 runs

Firefox 20 runs

Mobile Results:

Chrome 9 runs

Firefox 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

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