Benchmark: flatmap vs filtermap

Script Preparation code:

var test = [
  {
    id: 1,
    name: 1,
  },
  {
    id: 2,
    name: 12,
  },
  {
    id: 3,
    name: 13,
  },
  {
    id: 4,
    name: 14,
  },
  {
    id: 5,
    name: 15,
  },
  {
    id: 6,
    name: 16,
  }
]

Tests:

flatmap
new Map(test.flatMap(c => { if (c.id < 3) { return [] } return [[c.id, c]] }))
filter.map
new Map(test.filter(c => { return c.id >= 3 }).map(el => [el.id, el]))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
flatmap
filter.map

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided benchmark JSON and explain what's being tested.

**Benchmark Definition**

The benchmark compares two approaches to create a new Map from an array:

1. `flatMap`: A method introduced in ECMAScript 2017 (ES7) that creates a new array by calling a provided function for each element of the original array.
2. `filter` + `map`: A combination of two methods: `filter`, which creates a new array with only the elements that pass a test, and `map`, which applies a specified function to each element in the resulting array.

**Options Compared**

The benchmark compares the performance of these two approaches:

* `flatMap`
* `filter` + `map`

**Pros and Cons**

* **flatMap**: Pros:
	+ More concise and readable code
	+ Potential for better performance due to avoiding unnecessary iterations (e.g., filtering out elements before mapping)
	Cons:
	+ Introduced in ES7, which may not be supported by older browsers or environments.
* `filter` + `map`: Pros:
	+ Widely supported across browsers and environments
	Cons:
	+ More verbose code
	+ May incur additional overhead due to iterating over filtered elements

**Library and Special JavaScript Features**

There are no libraries used in this benchmark. However, the `flatMap` method is a modern JavaScript feature that was introduced in ES7.

**Other Considerations**

When choosing between these approaches, consider the trade-offs between readability, conciseness, and performance. If you need to support older browsers or environments that don't support ES7 features, `filter` + `map` might be a better choice. However, if you're targeting modern browsers and want more concise code, `flatMap` could be a better option.

**Other Alternatives**

If you're looking for alternative approaches to create a new Map from an array, consider:

* Using `Array.prototype.reduce()`: This method can achieve similar results as `flatMap` or `filter` + `map`, but with a more functional programming style.
* Using `Array.prototype.forEach()` and creating a new Map manually: This approach involves iterating over the original array and adding entries to a new Map using the `forEach` method. While not as concise as `flatMap` or `filter` + `map`, it can be an alternative solution.

Keep in mind that these alternatives might have different performance characteristics and trade-offs, so consider the specific requirements of your use case when choosing an approach.

Related benchmarks:

flatmap vs filtermap (version: 0)

Comparing performance of: flatmap vs filter.map

Created: 4 years ago by: Guest

Jump to the latest result

flatmap

filter.map

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):