Benchmark: Array vs Object vs Map vs WeakMap access2

Script Preparation code:

var map = new Map();
var weakMap = new WeakMap()
var array = [];
var object = {};

Tests:

Map.get
map.get("0");
WeakMap.get
weakMap.get("0")
array[0]
array[0]
object.a
object.a

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Map.get
WeakMap.get
array[0]
object.a

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36

Browser/OS: Chrome 96 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Map.get	15449838.0 Ops/sec
WeakMap.get	14299421.0 Ops/sec
array[0]	15393208.0 Ops/sec
object.a	15406374.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark JSON and its test cases to understand what is being tested.

**Benchmark Definition**

The `Script Preparation Code` section initializes variables for four data structures: an empty Map (`map`), a WeakMap (`weakMap`), an array (`array`), and an object (`object`). These variables are used as the targets for the subsequent test cases.

**Individual Test Cases**

Each test case defines a specific operation to perform on one of these data structures:

1. `Map.get("0")`: Accesses the first element (index 0) of the Map.
2. `WeakMap.get("0")`: Similar to above, but using a WeakMap.
3. `array[0]`: Directly accesses the first element of the array using bracket notation.
4. `object.a`: Similarly, accesses a property named "a" on the object.

These test cases are designed to measure the performance differences between accessing data structures in JavaScript.

**Pros and Cons of Different Approaches**

1. **Direct Access (array[0] and object.a)**:
	* Pros: Simple and straightforward.
	* Cons: May not be optimized by the JavaScript engine, potentially slower than other methods due to the need for explicit indexing.
2. **Map.get() and WeakMap.get()`:
	* Pros: Optimized by the JavaScript engine for accessing elements in these data structures. Can be faster due to caching and iteration optimization.
	* Cons: May require more memory allocation for the underlying Map or WeakMap, depending on the implementation.

**Library: `Map` and `WeakMap`**

These are built-in JavaScript data structures. A `Map` is an object that stores key-value pairs, while a `WeakMap` is similar but allows the keys to be garbage collected when they are no longer referenced.

The purpose of using these data structures in this benchmark is to test how quickly JavaScript engines can access elements within them.

**Special JS Features: None**

There are no special JavaScript features or syntax used in this benchmark beyond what's standard for accessing array and object elements.

**Other Alternatives**

If you wanted to create a similar benchmark, you could consider adding additional data structures, such as:

* `Set`: A data structure that stores unique values.
* `JSON.parse()` and `JSON.stringify()`: Functions for parsing and generating JSON strings.
* DOM-related operations: Accessing and manipulating HTML elements.

Keep in mind that the performance differences between these methods will depend on the specific JavaScript engine being used, as well as other factors like memory allocation and caching.

Related benchmarks:

Array vs Object vs Map vs WeakMap access2 (version: 0)

Comparing performance of: Map.get vs WeakMap.get vs array[0] vs object.a

Created: 3 years ago by: Guest

Jump to the latest result

Map.get

WeakMap.get

array[0]

object.a

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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