Benchmark: Map vs Object 10k iterations

Script Preparation code:

var map = new Map();
var obj = {};

map.set('a', 5);
obj['a'] = 5;

var i = 0, count = 10000, a;

Tests:

Map lookup
for (i = 0; i < count; i++) { a = map.get('a'); }
Obj lookup
for (i = 0; i < count; i++) { a = obj['a']; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map lookup
Obj lookup

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

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Let's break down the benchmark definition and results.

**What is being tested?**

The benchmark compares the performance of two data structures in JavaScript: `Map` vs `Object`. Specifically, it measures how fast it is to look up a value by key in both cases. The test case uses 10,000 iterations for each lookup operation.

**What options are compared?**

Two options are being compared:

1. **Map**: A JavaScript `Map` object is used as the data structure.
2. **Object**: A regular JavaScript object (i.e., a "hash table") is used instead of a `Map`.

**Pros and cons of each approach:**

* **Map**:
	+ Pros: More efficient for large datasets, as it uses a hash table internally, which allows for fast lookups.
	+ Cons: May have higher memory overhead due to the internal hash table structure.
* **Object** (regular JavaScript object):
	+ Pros: Lower memory overhead compared to `Map`.
	+ Cons: Less efficient for large datasets, as the lookup time increases with the size of the object.

**Other considerations:**

* The benchmark script prepares a `Map` and an empty object (`obj`) with one key-value pair each.
* The test cases iterate 10,000 times, looking up the value associated with key `'a'` in both data structures.
* The results show that the "Obj lookup" (i.e., using an object) has a slightly higher execution rate than the "Map lookup" (i.e., using a `Map`) on Chrome 98.

**Library used:**

None. This benchmark uses only built-in JavaScript features, such as `Map` and objects.

**Special JS feature or syntax:**

None are used in this benchmark. The code is straightforward and utilizes standard JavaScript features.

**Other alternatives:**

While not explicitly mentioned, some alternative approaches to using a `Map` or object for lookups could be:

* Using an indexed array (e.g., `Array.prototype.find()` or `Array.prototype.findIndex()`) for smaller datasets.
* Implementing a custom data structure with a more efficient lookup algorithm.
* Utilizing third-party libraries like Lodash's `_.find()` or underscore.js's `_.indexOf()`, which provide optimized implementations of various array and object operations.

These alternatives may have different trade-offs in terms of performance, memory usage, and ease of implementation.

Related benchmarks:

Map vs Object 10k iterations (version: 0)

Lookup of map vs object

Comparing performance of: Map lookup vs Obj lookup

Created: 4 years ago by: Guest

Jump to the latest result

Map lookup

Obj lookup

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):