Benchmark: Map read/write once vs twice (v2)

Script Preparation code:

var keys = [1, 2, 3, 4];
var mapObject = new Map();
var mapTime = new Map();
var mapDate = new Map();

Tests:

Once
const date = Date.now(); keys.forEach((key, i) => { const time = i * 1000; mapObject.set(key, {time, date}); }); keys.forEach((key) => { const {time, date} = mapObject.get(key); });
Twice
const date = Date.now(); keys.forEach((key, i) => { const time = i * 1000; mapTime.set(key, time); mapDate.set(key, date); }); keys.forEach((key) => { mapTime.get(key); mapDate.get(key); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Once
Twice

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/126.0.0.0 YaBrowser/24.7.0.0 Safari/537.36

Browser/OS: Yandex Browser 24 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Once	1419444.0 Ops/sec
Twice	942110.6 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 Overview**

The benchmark is designed to measure the performance of accessing a Map object in JavaScript, specifically whether it's faster to read from a Map once or twice. The tests are comparing two approaches:

1. **Once**: Reading from a Map only once using `mapObject.get(key)`.
2. **Twice**: Reading from a Map twice using `mapTime.get(key)` and `mapDate.get(key)`.

**Options Compared**

The benchmark is comparing the performance of accessing a Map object in different ways:

* **Single read**: Accessing the value associated with a key once.
* **Double read**: Accessing the same value associated with a key twice.

**Pros and Cons of Each Approach**

1. **Once (Single Read)**:
	* Pros:
		+ Faster, as it only involves a single access to the Map object.
		+ Less memory usage, as only one value is retrieved.
	* Cons:
		+ May not accurately reflect real-world scenarios where data needs to be accessed multiple times.
2. **Twice (Double Read)**:
	* Pros:
		+ More representative of real-world use cases, where data is often accessed multiple times.
	* Cons:
		+ Slower and more memory-intensive due to the additional access.

**Library Used**

None.

**Special JS Feature/Syntax**

No special JavaScript features or syntax are used in this benchmark. The code is simple and straightforward, making it easy to understand for a wide range of developers.

**Other Alternatives**

To test similar performance scenarios, you could consider benchmarks that compare:

* Accessing an object using a different data structure (e.g., arrays, JSON objects).
* Optimizing Map performance by resizing or reusing the underlying array.
* Using caching mechanisms to reduce Map access frequency.
* Comparing performance across different JavaScript engines (e.g., V8, SpiderMonkey) or browsers.

Keep in mind that these alternatives may not be as directly comparable to this specific benchmark, but they can still provide valuable insights into optimizing JavaScript performance.

Related benchmarks:

Map read/write once vs twice (v2) (version: 1)

Comparing performance of: Once vs Twice

Created: one year ago by: Registered User

Jump to the latest result

Once

Twice

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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