Benchmark: Object iteration vs Map iteration 2

Script Preparation code:

var obj = {
  a: 1,
  b: 2,
  c: 3,
  d: 4,
  e: 5,
  f: 6,
  g: 7,
  h: 8,
  i: 9,
  j: 10,
  k: 11,
  l: 12,
  m: 13,
  n: 14,
  o: 15,
  p: 16,
  q: 17,
  r: 18,
  s: 19,
  t: 20,
  u: 21,
  v: 22,
  w: 23,
  x: 24,
  y: 25,
  z: 26
};
var map = new Map(Object.entries(obj));

var arr = new Array(Object.values(obj));

Tests:

array.forEach
let a = 0; arr.forEach((v) => { a += v; });
map.forEach
let a = 0; map.forEach((v, k) => { a += v; });
object for
let a = 0; for(const k in obj){ a += obj[k]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.forEach
map.forEach
object for

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36

Browser/OS: Chrome 116 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
array.forEach	2294832.2 Ops/sec
map.forEach	4476068.0 Ops/sec
object for	700963.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark is designed to compare the performance of three different approaches for iterating over an object: `array.forEach`, `map.forEach`, and `object for`. The test case uses a large object with 26 properties, which is populated into both an array (`arr`) and a Map (`map`).

**Options Compared**

The two main options being compared are:

1. **Array iteration using `forEach`**: This method iterates over the values of the array, but does not provide access to the index or key-value pairs.
2. **Map iteration using `forEach`**: This method iterates over both the keys and values of the Map, providing access to the key-value pairs.

**Pros and Cons**

* **Array Iteration (`array.forEach`)**:
	+ Pros: Easy to implement, widely supported, and well-documented.
	+ Cons: Does not provide access to the index or key-value pairs, which may be necessary for certain use cases.
* **Map Iteration (`map.forEach`)**:
	+ Pros: Provides access to both keys and values, making it a good choice when working with Map-like data structures.
	+ Cons: May have higher overhead due to the additional data being accessed (keys).

**Other Considerations**

* The test case does not include any special JavaScript features or syntax that would affect the performance of these iterations. However, if you were to add more complex logic or use specific features like `async/await` or `promises`, it could impact the results.
* The benchmark also does not account for other factors that may affect performance, such as the size of the input data, caching, or optimization techniques.

**Library and Purpose**

The `Map` data structure is a built-in JavaScript object that stores key-value pairs. It provides methods like `forEach`, `get()`, and `set()` to interact with the data.

**Explanation of `map.forEach` syntax**

In the benchmark code, `map.forEach((v, k) => { ta += v; });` iterates over both the keys (`k`) and values (`v`) of the Map. This allows the function to access the key-value pairs and perform operations on both.

Overall, this benchmark helps users understand the performance characteristics of different iteration methods in JavaScript, which can be useful when working with large datasets or optimizing code for better performance.

Related benchmarks:

Object iteration vs Map iteration 2 (version: 0)

Comparing performance of: array.forEach vs map.forEach vs object for

Created: one year ago by: Guest

Jump to the latest result

array.forEach

map.forEach

object for

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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