Benchmark: map vs object wqe21123

Tests:

object
// Create sample data var array = {};
map
// Create sample data var array = new Map();

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: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser/OS: Chrome 135 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
object	178386288.0 Ops/sec
map	55320584.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The benchmark in question compares two different data structures in JavaScript: a plain object (`{}`) and a `Map` object. Here’s a breakdown of what is tested and the considerations around it.

### Tested Options

1. **Object**
   - **Test Name:** `object`
   - **Benchmark Definition:** `var array = {};` (initializing a plain object)
   - **Notes:** Plain objects in JavaScript are key-value pairs that allow the storage of unordered collections.

2. **Map**
   - **Test Name:** `map`
   - **Benchmark Definition:** `var array = new Map();` (initializing a Map)
   - **Notes:** `Map` is a built-in JavaScript object that holds key-value pairs where keys can be any datatype. Maps maintain the insertion order of keys.

### Pros and Cons

#### Objects
**Pros:**
- Lightweight and faster for simple use cases due to lower overhead.
- Syntactic simplicity: object literals (`{}`) are easy to use and integral to JavaScript.

**Cons:**
- The keys in objects are limited to strings or symbols. If a non-string is used as a key, it will be automatically converted to a string.
- Object properties can have prototype properties/methods which may lead to unintentional key collisions.

#### Maps
**Pros:**
- Keys can be of any type, including objects, functions, and primitives.
- Maps are optimized for frequent additions and removals of key-value pairs, making them more performant in dynamic scenarios.
- They maintain insertion order, which can be crucial for certain applications.

**Cons:**
- Slightly more overhead in terms of memory due to additional functionality and flexibility.
- Syntax for instantiation and operations is more verbose (e.g., `new Map()` vs. `{}`).

### Benchmark Results

The benchmark results demonstrate the performance of both structures, measured in `ExecutionsPerSecond`. Here are the results:

- **Object:** 178,386,288 executions per second
- **Map:** 55,320,584 executions per second

From the results, we can see that the plain object outperformed the Map by a significant margin, which is expected given that objects typically have less overhead.

### Other Alternatives

Apart from objects and Maps, there are other data structures in JavaScript that can be used, depending on the specific requirements:

1. **Set**: If you only need to store unique values and do not care about keys or associated values, a Set is a good option.
   
2. **WeakMap**: Similar to Map, but the keys are weakly referenced. They can be garbage collected if there are no other references to them. Used for object caches without preventing garbage collection.

3. **WeakSet**: A Set that holds weakly referenced objects which can also be garbage collected.

Each data structure has its specific use-case and understanding these differences helps in choosing the right one based on performance and functionality needs.

Related benchmarks:

map vs object wqe21123 (version: 1)

Comparing performance of: object vs map

Created: one year 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 gpt-4o-mini, generated one year ago):