Benchmark: WeakMap vs Symbol Property vs String Property

Script Preparation code:

var to0 = {};
var to1 = {};
var to2 = {};
var wm = new WeakMap();
var sy = Symbol();
var prop = 'aaa'
wm.set(to1, 1);
to1[sy] = 1;
to2[prop] = 1;

Tests:

WeakMap set
wm.set(to0, 1);
Symbol Property set
to0[sy] = 1;
WeakMap get
let r = wm.get(to1);
Symbol Property get
let r = to1[sy];
String Property set
to2[prop] = 1;
String Property get
let r = to2[prop];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
WeakMap set
Symbol Property set
WeakMap get
Symbol Property get
String Property set
String Property get

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
WeakMap set	11643148.0 Ops/sec
Symbol Property set	12471522.0 Ops/sec
WeakMap get	11771086.0 Ops/sec
Symbol Property get	12468970.0 Ops/sec
String Property set	12397484.0 Ops/sec
String Property get	12486915.0 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 and explain what is being tested.

**Benchmark Overview**

The benchmark measures the performance of three different property access methods: WeakMap, Symbol Property, and String Property (using bracket notation). The test case consists of six individual tests:

1. Setting a value in a WeakMap
2. Setting a value using a Symbol Property
3. Getting a value from a WeakMap
4. Getting a value using a Symbol Property
5. Setting a value using a String Property
6. Getting a value using a String Property (with bracket notation)

**Options Compared**

The benchmark compares the performance of three different approaches:

1. **WeakMap**: A WeakMap is a hash map that uses weak references for keys. This means that the key object can be garbage collected if it's no longer referenced elsewhere.
2. **Symbol Property**: Symbol properties are a new way to create property descriptors in JavaScript. They provide faster lookups than traditional string-based property access.
3. **String Property** (using bracket notation): This is the traditional way of accessing properties using string literals.

**Pros and Cons**

* **WeakMap**:
	+ Pros: Fast lookups, garbage collection helps with memory management.
	+ Cons: Weak references can lead to unexpected behavior if not used carefully.
* **Symbol Property**:
	+ Pros: Faster lookups than traditional property access, more flexible than string-based notation.
	+ Cons: Not all browsers support Symbol properties, and older versions of Internet Explorer may interpret them differently.
* **String Property** (using bracket notation):
	+ Pros: Wide browser support, simple to use.
	+ Cons: Slower lookups compared to WeakMap or Symbol Property.

**Library Used**

In this benchmark, the `WeakMap` data structure is used from the built-in JavaScript API. No external libraries are required.

**Special JS Features/Syntax**

The benchmark uses Symbol properties, which is a relatively new feature in JavaScript introduced in ECMAScript 2015 (ES6). It provides faster and more efficient way to access properties compared to traditional string-based notation.

**Other Alternatives**

For those who may be interested in exploring alternative approaches, here are some other options:

* **Object Property**: This is the traditional way of accessing properties using dot notation or bracket notation. While not as fast as WeakMap or Symbol Property, it's still a viable option for many use cases.
* **Proxy Objects**: Proxies provide a more flexible and dynamic way to control property access and behavior. However, they may introduce additional overhead compared to WeakMap or Symbol Property.

In summary, this benchmark measures the performance of three different property access methods: WeakMap, Symbol Property, and String Property (using bracket notation). The results can help developers understand which approach is best suited for their specific use cases, considering factors like performance, memory management, and browser compatibility.

Related benchmarks:

WeakMap vs Symbol Property vs String Property (version: 0)

Comparing performance of: WeakMap set vs Symbol Property set vs WeakMap get vs Symbol Property get vs String Property set vs String Property get

Created: one year ago by: Guest

Jump to the latest result

WeakMap set

Symbol Property set

WeakMap get

Symbol Property get

String Property set

String Property 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):