Benchmark: Map vs Object - More items2

Script Preparation code:

var map = new Map();
var obj = {};
for (let i = 0; i < 50; i++) {
  map.set('a' + i, i);
  obj['a' + i] = i;
}
Object.freeze(obj)

var i = 0, count = 1000, 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:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Windows

View result in a separate tab

Test name	Executions per second
Map lookup	6970.2 Ops/sec
Obj lookup	6952.8 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 JSON data for the MeasureThat.net JavaScript microbenchmark.

**Benchmark Definition**

The benchmark is comparing two approaches: using a `Map` and using an object (`obj`) to store and look up values. The purpose of this comparison is to determine which approach is faster for large datasets.

**Options Compared**

There are two options being compared:

1. **Map Lookup**: Using the `get()` method on a `Map` object to retrieve values by key.
2. **Object Lookup**: Using the bracket notation (`obj['a']`) to access values in an object.

**Pros and Cons of Each Approach**

**Map Lookup:**

Pros:

* Faster lookups, especially for large datasets, since maps are designed for efficient key-value pairs.
* Can handle duplicate keys without issues.

Cons:

* May have a higher overhead due to the need to create and manage a map instance.
* Not as intuitive or familiar for many developers.

**Object Lookup:**

Pros:

* More familiar and easier to understand for many developers, especially those with experience in other languages.
* Does not require the creation of an additional object instance.

Cons:

* Can be slower for large datasets due to the need to perform string concatenation and lookup.
* May have issues with duplicate keys, depending on how they are handled (e.g., overwriting existing values).

**Library Used**

In this benchmark, the `Map` class is used from the JavaScript Standard Library. This provides an efficient and well-maintained implementation of maps.

**Special JS Feature or Syntax**

There is no special JS feature or syntax being tested in this benchmark. The focus is on comparing two fundamental approaches to data storage and retrieval.

**Other Considerations**

This benchmark is a great example of how MeasureThat.net helps developers compare performance differences between different JavaScript approaches. By running multiple iterations with varying numbers of items (in this case, 50), the results provide a more accurate representation of the performance differences between map lookup and object lookup.

For those interested in learning more about maps in JavaScript, there are many resources available, including MDN Web Docs' documentation on `Map` objects.

**Alternatives**

Other alternatives for comparing data storage and retrieval approaches include:

* Using an array instead of a map or object.
* Implementing your own custom data structure (e.g., using a binary search tree).
* Using a different language or implementation for the benchmark, such as Node.js with V8.

Keep in mind that the choice of alternative depends on the specific requirements and goals of the project.

Related benchmarks:

Map vs Object - More items2 (version: 0)

Lookup of map vs object

Comparing performance of: Map lookup vs Obj lookup

Created: one year ago by: Guest

Jump to the latest result

Map lookup

Obj lookup

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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