Benchmark: Map.get vs Object[i] vs Map.has

Script Preparation code:

var map = new Map([[1, 1]]);
var obj = {1: 1};
var count = 100; 
var a, i;


for (let j = 0; j < count; j++) {
  map.set(j, j);
  obj[j] = j;
}

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Obj get
Map get
Map has

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.4 Safari/605.1.15

Browser/OS: Safari 18 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Obj get	14151171.0 Ops/sec
Map get	3702161.2 Ops/sec
Map has	3797199.2 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Description**

The benchmark is comparing three ways to access elements in an object or a Map:

1. `Object[i]` (Accessing an element using bracket notation)
2. `Map.get(i)` (Accessing an element using the `get()` method of the Map interface)
3. `Map.has(i)` (Testing if an element exists using the `has()` method of the Map interface)

**Options Compared**

The benchmark is comparing the performance of these three approaches:

* **Object[i]**: This approach uses the bracket notation to access elements in the object. It's a simple and direct way to access elements, but it may not be as efficient as other methods.
* **Map.get(i)**: This approach uses the `get()` method of the Map interface to access elements. The `get()` method is designed to retrieve values from maps and returns `undefined` if the key is not found.
* **Map.has(i)**: This approach uses the `has()` method of the Map interface to test if an element exists. However, unlike the `get()` method, `has()` does not return a value; it simply returns a boolean indicating whether the key exists.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

* **Object[i]**:
	+ Pros: Simple, efficient, and widely supported.
	+ Cons: May not be as efficient for large objects or maps, and it can lead to issues if the object is modified while accessing elements.
* **Map.get(i)**:
	+ Pros: Designed for retrieving values from maps, returns a value (or `undefined`), and is efficient for large maps.
	+ Cons: May not be as efficient for small objects or arrays, and it's specific to Map interfaces.
* **Map.has(i)**:
	+ Pros: Simple, efficient, and specific to Map interfaces.
	+ Cons: Returns a boolean value instead of the actual element, which may require additional processing.

**Library/Functions**

The benchmark uses two built-in JavaScript functions:

* `Map.get()`: Retrieves values from maps.
* `Map.has()`: Tests if an element exists in maps.

No external libraries are required for this benchmark.

**Special JS Feature/Syntax**

There's no special JavaScript feature or syntax used in this benchmark. The code is standard JavaScript, using the basic features and syntax available.

**Alternatives**

If you're interested in exploring alternative approaches, here are a few options:

* **Using `in` operator**: Instead of bracket notation (`Object[i]`) or map methods (`Map.get()`/`Map.has()`), you could use the `in` operator to access elements. For example: `var a = obj['i'];`
* **Using object iteration**: You could iterate over the object or map using a for loop, like this: `for (var i in obj) { var a = obj[i]; }`
* **Using array methods**: If you're working with arrays instead of objects or maps, you could use array methods like `Array.prototype.slice()` or `Array.prototype.indexOf()`

Keep in mind that these alternatives may have different performance characteristics and might not be as efficient as the original approaches.

I hope this explanation helps!

Related benchmarks:

Map.get vs Object[i] vs Map.has (version: 0)

Comparing performance of: Obj get vs Map get vs Map has

Created: 4 years ago by: Guest

Jump to the latest result

Obj get

Map get

Map has

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):