Benchmark: Anonymous Callback vs Function Bind

Tests:

callback
const callback = (result, result2) => console.log(result + result2) function init() { new Promise((resolve) => { resolve("my return") }).then(result => callback(result, " result 2")) } init()
bind
const callback = (result, result2) => console.log(result + result2) function init() { new Promise((resolve) => { resolve("my return") }).then(callback.bind(null, "return 2")) } init()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
callback
bind

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:95.0) Gecko/20100101 Firefox/95.0

Browser/OS: Firefox 95 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
callback	296679.8 Ops/sec
bind	208355.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is an essential task for any software engineer. Let's dive into the provided benchmark and explore what's being tested.

**Benchmark Overview**

The provided benchmark compares two approaches to executing callbacks in JavaScript:

1. **Anonymous Callback**: This approach uses an anonymous function (i.e., a function without a declared name) as the callback.
2. **Function Bind**: This approach binds a function to `null` before passing it as the callback.

**Options Compared**

The benchmark is comparing the performance of these two approaches on JavaScript's event loop. The key differences between them are:

* **Function creation overhead**: In the anonymous callback approach, the function is created at runtime, while in the function bind approach, the function is already defined and bound to `null`.
* **Context preservation**: When using an anonymous callback, the context (i.e., `this`) of the callback function is determined by the surrounding scope. In contrast, when using function bind, the context is explicitly set to `null`.

**Pros and Cons**

* **Anonymous Callback**:
	+ Pros: Easy to write, no explicit binding required.
	+ Cons: Function creation overhead can be significant due to the anonymous function creation.
* **Function Bind**:
	+ Pros: Reduces function creation overhead since the function is already defined, and context preservation is ensured.
	+ Cons: More verbose code, requires explicit binding.

In general, when performance is critical, using a function bind approach can lead to better performance due to reduced function creation overhead. However, this comes at the cost of increased code verbosity.

**Library/Functionality Used**

The benchmark uses JavaScript's built-in `Promise` API and the `bind()` method.

* **Promise**: A promise represents an asynchronous operation that may or may not have completed yet.
* **bind()**: The `bind()` method creates a new function that has its `this` keyword set to the provided value. This is used here to preserve the context of the callback function when passed to the `then()` method.

**Special JS Feature/Syntax**

The benchmark uses JavaScript's arrow functions, which were introduced in ECMAScript 2015 (ES6). Arrow functions provide a concise syntax for defining small anonymous functions and can help reduce code verbosity. In this case, the arrow function is used as the callback in both test cases.

**Other Alternatives**

Alternative approaches to executing callbacks could include:

* **Immediately Invoked Function Expression (IIFE)**: Creating a new scope using an IIFE can help avoid global variables and improve encapsulation.
* **Constructor Functions**: Using constructor functions can provide a more explicit way of creating objects and handling callbacks.
* **Async/Await**: Using async/await syntax can simplify callback-heavy code and reduce the need for explicit promise chaining.

Keep in mind that each approach has its pros and cons, and the choice ultimately depends on the specific use case and performance requirements.

Related benchmarks:

Anonymous Callback vs Function Bind (version: 0)

Comparing performance of: callback vs bind

Created: 3 years ago by: Guest

Jump to the latest result

callback

bind

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):