Benchmark: reduce/concat vs flatMap

Script Preparation code:

var server = {
	routes: [
      ['v1', { url: 'v1' }],
      ['v2', { url: 'v2' }]
    ]
}

Tests:

reduce/concat
const routes = Array.from(server.routes).reduce((routes, [_, route]) => { return routes.concat(route); }); console.log(routes)
flatMap
const routes = Array.from(server.routes).flatMap((routes) => { const [_, route] = routes; return route; }); console.log(routes)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce/concat
flatMap

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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.

**Benchmark Overview**

The provided benchmark compares two approaches to flatten an array of routes: `reduce` and `flatMap`. The test case uses a simple server object with two routes, each containing a URL. The goal is to extract these URLs and store them in a single array.

**Script Preparation Code**

The script preparation code defines a `server` object with an array of routes:
```javascript
var server = {
  routes: [
    ['v1', { url: 'v1' }],
    ['v2', { url: 'v2' }]
  ]
};
```
This code sets up the data structure used for the benchmark.

**Html Preparation Code**

There is no HTML preparation code provided, which means that this benchmark focuses solely on the JavaScript implementation and does not consider any additional factors like DOM manipulation or network interactions.

**Benchmark Options**

The two benchmark options are:

1. `reduce`
2. `flatMap`

Let's discuss each option:

### `reduce` approach

The `reduce` method applies a callback function to each element in the array, accumulating a result. In this case, we use it to flatten the routes by concatenating each route's URL:
```javascript
const routes = Array.from(server.routes).reduce((routes, [_, route]) => {
  return routes.concat(route);
}, []);
```
Pros:

* Can be more intuitive for some developers who are familiar with `reduce`.
* Allows for flexibility in handling different types of data.

Cons:

* Has a higher overhead due to the accumulation step.
* Can lead to performance issues if the input array is very large.

### `flatMap` approach

The `flatMap` method returns a new array by mapping each element of the original array and then flattening the resulting array. In this case, we use it to flatten the routes by extracting each route's URL:
```javascript
const routes = Array.from(server.routes).flatMap((routes) => {
  const [_, route] = routes;
  return route;
});
```
Pros:

* Has lower overhead compared to `reduce`.
* Returns a new array without accumulating intermediate results.

Cons:

* May be less intuitive for some developers who are not familiar with `flatMap`.
* Can lead to memory issues if the input array is very large.

**Library and Special JS Feature**

In this benchmark, there is no explicit library mentioned. However, both approaches rely on built-in JavaScript methods (`reduce` and `flatMap`). There are no special JS features used beyond these standard methods.

**Other Alternatives**

If you want to explore alternative approaches, here are a few options:

1. **Using `forEach`**: You can use the `forEach` method to iterate over the routes array and accumulate the results in an array:
```javascript
const routes = [];
server.routes.forEach(([_, route]) => {
  routes.push(route.url);
});
```
This approach is less efficient than both `reduce` and `flatMap`, as it involves a separate loop.

2. **Using `Array.prototype.map`**: You can use the `map` method to create a new array with the flattened URLs:
```javascript
const routes = server.routes.map(([_, route]) => route.url);
```
This approach is less efficient than both `reduce` and `flatMap`, as it creates an additional intermediate array.

In conclusion, the `reduce` and `flatMap` approaches are two effective ways to flatten an array of routes in JavaScript. The choice between them depends on personal preference, familiarity with the methods, and performance considerations.

Related benchmarks:

reduce/concat vs flatMap (version: 0)

Comparing performance of: reduce/concat vs flatMap

Created: 3 years ago by: Guest

Jump to the latest result

reduce/concat

flatMap

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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