Benchmark: Object access by key vs Map.get

Script Preparation code:

var map = new Map();
map.set("foo", "bar");

var obj = { foo: "bar" };

Tests:

Object access
var value = obj["foo"];
Map.get
var value = map.get("foo");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object access
Map.get

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36

Browser/OS: Chrome 79 on Windows

View result in a separate tab

Test name	Executions per second
Object access	2234751.2 Ops/sec
Map.get	2630159.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this JavaScript benchmark.

**Benchmark Definition**

The benchmark is comparing two approaches to accessing an object or map value: `obj[key]` (i.e., dot notation) and `map.get(key)` (i.e., Map's built-in method).

**Options Compared**

Two options are compared:

1. **Object access using dot notation (`obj[key]`)**
2. **Map access using `map.get(key)`**

**Pros and Cons of Each Approach**

1. **Object Access using Dot Notation (`obj[key]`)**:
	* Pros:
		+ Familiar syntax for most developers.
		+ Can be faster if the object is small or already cached in memory.
	* Cons:
		+ May involve more computations (e.g., string comparison) than `map.get`.
		+ May not work efficiently with large objects or when dealing with keys that are not hashable.
2. **Map Access using `map.get(key)`**:
	* Pros:
		+ Built-in, optimized method for accessing map values, often implemented in native code.
		+ Can be faster and more efficient than dot notation, especially for large maps.
	* Cons:
		+ Requires a Map object to be created, which may incur some overhead.
		+ May not work if the key is not hashable (e.g., if it's an array or object).

**Library Used**

In this benchmark, the `Map` library is used. Maps are a data structure in JavaScript that store key-value pairs, allowing for efficient lookups and insertions.

**Special JS Feature or Syntax**

The benchmark uses ES6+ syntax, specifically:

* The `Map` constructor (`var map = new Map();`)
* The `get()` method of the Map object (`map.get(key)`)

These features are part of the modern JavaScript standard library and have been widely adopted in recent years.

**Other Alternatives**

If you wanted to benchmark other approaches to accessing object or map values, some alternatives could include:

* Using a different data structure, such as an array with an index or a JSON object.
* Implementing your own lookup function using bitwise operations or arithmetic.
* Using a library like Lodash or Ramda for more functional programming style.

However, it's worth noting that `map.get()` is often the recommended approach in modern JavaScript development due to its efficiency and readability.

Related benchmarks:

Object access by key vs Map.get (version: 0)

Comparing performance of: Object access vs Map.get

Created: 4 years ago by: Guest

Jump to the latest result

Object access

Map.get

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):