Benchmark: Promise vs. Callback

Tests:

callback
function run(then){then()} run(()=>{});
promise
function run(){return Promise.resolve()} run().then(()=>{})

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
callback
promise

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Linux

View result in a separate tab

Test name	Executions per second
callback	140046304.0 Ops/sec
promise	8110674.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is tested:**

The provided benchmark compares two approaches for handling asynchronous operations in JavaScript: callbacks and Promises. Specifically, it tests the performance difference between executing callback functions versus using Promise APIs to handle a simple operation: resolving with an empty value.

**Options compared:**

There are two main options being compared:

1. **Callbacks**: In this approach, a function is executed immediately, and its result is passed as an argument to another function, which then processes the result.
2. **Promises**: This option uses the Promise API to handle asynchronous operations. A Promise object represents a value that may not be available yet, but will be resolved at some point in the future.

**Pros and Cons of each approach:**

**Callbacks:**

Pros:

* Simple to understand and implement
* Widely supported in older browsers

Cons:

* Can lead to callback hell (nested callbacks), making code harder to read and maintain
* Difficult to handle errors, as they are not propagated naturally

**Promises:**

Pros:

* Easier to read and write than callbacks
* Allows for better error handling and more flexible execution of asynchronous operations
* Widely supported in modern browsers

Cons:

* Can be slower than callbacks due to the overhead of creating and managing Promise objects

**Other considerations:**

When choosing between callbacks and Promises, consider the following factors:

* **Complexity**: If you need to handle complex asynchronous operations with multiple steps, Promises might be a better choice.
* **Error handling**: If you want to handle errors in a more elegant way, Promises are generally a better option.
* **Browser support**: While both approaches have good browser support, Promises have become the de facto standard in modern JavaScript development.

**Library usage:**

In this benchmark, no specific libraries are used. The code is self-contained and demonstrates the basic principles of callbacks and Promises.

**Special JS features or syntax:**

There's one notable feature used in this benchmark:

* **Arrow functions**: Both callback and Promise implementations use arrow functions (anonymous functions without a `function` keyword). This is a modern JavaScript feature that allows for more concise code.

Overall, this benchmark provides a simple yet informative comparison between two popular approaches to handling asynchronous operations in JavaScript.

Related benchmarks:

Promise vs. Callback (version: 0)

Comparing performance of: callback vs promise

Created: 5 years ago by: Guest

Jump to the latest result

callback

promise

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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