Benchmark: Object vs map incrementing

Tests:

Object
const person = { name: "Alice" } const obj = { [person.name]: 0 } for (let i = 0; i < 1000000; i++) { obj[person.name]++ }
Map
const person = { name: "Alice" } const map = new Map() map.set(person.name, 0) for (let i = 0; i < 1000000; i++) { map.set(person.name, map.get(person.name) + 1) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object
Map

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object	1034.9 Ops/sec
Map	94.0 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 explain what's being tested, compared, and other considerations.

**Benchmark Overview**

The provided benchmark measures the performance difference between using objects and Maps in JavaScript for incrementing a key-value pair 1 million times.

**Options Compared**

Two options are being compared:

1. **Objects**: The first test case uses an object to store the key-value pair and increments it.
2. **Maps**: The second test case uses a Map data structure to store the key-value pair and increments it.

**Pros and Cons of Each Approach**

### Objects

Pros:

* Objects are lightweight and easy to use, especially for simple key-value pairs.
* Objects have built-in support for property access and incrementing (e.g., `obj[person.name]++`).

Cons:

* Objects can be slower than Maps for large datasets due to the overhead of accessing properties using bracket notation (`obj[person.name]`).
* Objects may not provide the same level of performance as Maps when dealing with large numbers of keys.

### Maps

Pros:

* Maps are designed specifically for storing key-value pairs and provide fast lookups, insertions, and deletions.
* Maps have better performance than objects for large datasets due to their optimized implementation.

Cons:

* Maps require more code to use compared to objects (e.g., `map.set(person.name, 0)` and `map.get(person.name) + 1`).
* Maps may have a higher memory footprint than objects due to the overhead of storing additional metadata (e.g., key-value pairs).

**Library and Syntax Considerations**

The benchmark uses no external libraries. However, it does use some JavaScript features specific to modern browsers:

* Bracket notation (`obj[person.name]`) is used for property access.
* The `++` operator is used for incrementing the value.

These features are widely supported in modern browsers, but may not be compatible with older browsers or environments that don't support them.

**Other Alternatives**

If you're considering using objects or Maps for similar use cases, here are some alternative approaches:

* **Arrays**: You could use arrays to store the key-value pairs and increment the value at a specific index. However, this approach would require more code and might not be as efficient as using Maps.
* **Indexed Collections**: Some JavaScript engines provide indexed collections (e.g., `Object.keys()` and `Set`) that can be used for storing key-value pairs. These collections offer performance similar to Maps but with slightly different APIs.

**Benchmark Preparation Code**

The provided benchmark preparation code is minimal, which means it's likely that the test cases are designed to focus on the performance differences between objects and Maps. The code typically includes:

* A sample data structure (e.g., an object or Map) initialized with a key-value pair.
* A loop that increments the value at that key 1 million times.

In this case, the preparation code is mostly blank, indicating that the focus is on measuring performance rather than executing arbitrary JavaScript code.

Related benchmarks:

Object vs map incrementing (version: 0)

Comparing performance of: Object vs Map

Created: 2 years ago by: Guest

Jump to the latest result

Object

Map

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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