Benchmark: Object vs Map 2022 new

Script Preparation code:

var map = new Map();
var obj = {};
var i, count = 1000, a;

keys = new Array(count)
for (i = 0; i < count; i++) {
  keys[i] = Math.random().toString()
  map.set(keys[i], { value: Math.random().toString() });
  obj[keys[i]] = { value: Math.random().toString() };
}

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map lookup
Array lookup

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its test cases.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark that compares the performance of two data structures: Objects and Maps. Specifically, it tests the lookup performance of each data structure using an array of keys.

**Options compared**

There are only two options being compared:

1. **Object Lookup**: This uses an object literal to store key-value pairs, where the value is another object with a random string as its property.
2. **Map Lookup**: This uses a Map data structure to store key-value pairs, where the key is a random string and the value is another object with a random string as its property.

**Pros and Cons**

* **Object Lookup**:
	+ Pros: Simple to implement, widely supported by browsers.
	+ Cons: Can lead to slower performance due to the need to access properties using bracket notation (e.g., `obj[keys[i]].value`).
* **Map Lookup**:
	+ Pros: Typically faster than object lookup due to the optimized lookup mechanism in Maps.
	+ Cons: Less widely supported by older browsers, may require additional setup.

**Library and its purpose**

In this benchmark, the Map data structure is used from the built-in JavaScript `Map` class. The purpose of using a Map is to take advantage of its optimized lookup mechanism, which is typically faster than accessing properties using bracket notation in objects.

**Special JS feature or syntax**

None mentioned in the provided code snippets. However, it's worth noting that some modern browsers support additional features like `const` and `let` declarations for variable scope, but they are not relevant to this specific benchmark.

**Other alternatives**

If you were to implement a similar benchmark, you could consider using other data structures or approaches, such as:

* Using an Array with indices: Instead of using objects or Maps, you could use an array with indices to store and retrieve values.
* Using a Set: A Set is another collection type that provides fast lookup times, but it's typically used for unique values only.

In summary, the benchmark compares the performance of object lookup and map lookup in JavaScript, highlighting the advantages of using Map data structures for optimized lookup performance.

Related benchmarks:

Object vs Map 2022 new (version: 1)

Comparing performance of: Map lookup vs Array lookup

Created: 3 years ago by: Registered User

Jump to the latest result

Map lookup

Array lookup

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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