Benchmark: comparing flatMap vs filter and map in little arr length

Script Preparation code:

var arr = [];
let i = 0;

while (i <= 100) arr[i] = i++;

Tests:

filter & map
arr.filter(x => x % 3).map(x => x/100)
flatMap
arr.flatMap(x => x % 3 ? x/100 : [])

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
filter & map
flatMap

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
filter & map	2062298.6 Ops/sec
flatMap	701899.3 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided JSON represents a benchmark test on MeasureThat.net, which compares the performance of two JavaScript methods: `filter()` and `map()`, versus their combined alternative in the `flatMap()` method.

**Methods Compared**

1. **Filter() + Map()**: This approach involves using `filter()` to filter elements from an array, followed by `map()` to transform each remaining element.
2. **FlatMap()**: The alternative approach uses `flatMap()` to achieve a similar transformation as the combined `filter()` and `map()` approach in a single step.

**Pros and Cons of Each Approach**

1. **Filter() + Map()**:
	* Pros: Easier to understand for developers familiar with `filter()` and `map()`.
	* Cons: Requires two separate method calls, which can lead to higher overhead due to function call overhead.
2. **FlatMap()**:
	* Pros: Can be more efficient since it combines the filtering and transformation steps into a single operation.
	* Cons: Less intuitive for developers unfamiliar with `flatMap()`.

**Library**

None of the benchmark tests explicitly use any external libraries.

**Special JavaScript Feature/ Syntax**

The benchmark test does not use any special JavaScript features or syntax, such as async/await, ES6 classes, or other modern language features.

**Other Alternatives**

If you need to compare performance of array operations in JavaScript, other alternatives include:

1. Using the `forEach()` method instead of `filter()`, `map()`, and `flatMap()`.
2. Using a library like Lodash or Ramda for functional programming operations.
3. Implementing custom iteration logic using loops.

Keep in mind that these alternatives may have different performance characteristics depending on the specific use case.

**Benchmark Preparation Code Explanation**

The provided preparation code generates an array of 100 elements and assigns each element a value from 0 to 99:

```javascript
var arr = [];
let i = 0;
while (i <= 100) arr[i] = i++;
```

This code creates an array with values from 0 to 99, which is used as input for the benchmark tests.

**Individual Test Cases Explanation**

Each test case compares the performance of a specific pair of methods:

1. **Filter() + Map()**: This test case uses `filter()` to filter elements where `x % 3` returns true, followed by `map()` to transform each remaining element.
2. **FlatMap()**: This test case uses `flatMap()` to achieve a similar transformation as the combined `filter()` and `map()` approach in a single step.

The benchmark result shows the raw UA string, browser version, device platform, operating system, executions per second for each test case.

Related benchmarks:

comparing flatMap vs filter and map in little arr length (version: 0)

Comparing performance of: flatMap() vs filter().map()

Comparing performance of: filter & map vs flatMap

Created: one year ago by: Guest

Jump to the latest result

filter & map

flatMap

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):