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flat vs flatMap vs reduce vs dumb
(version: 0)
Comparing performance of:
reduce vs flatMap vs flat vs dumb
Created:
3 years ago
by:
Guest
Jump to the latest result
Script Preparation code:
var arr = Array(10_000).fill(Array(20).fill(Math.random()*50))
Tests:
reduce
arr.reduce((acc, val) => acc.concat(val), [])
flatMap
arr.flatMap(x => x)
flat
arr.flat()
dumb
arr.reduce((acc, val) => { if (val) { val.forEach((x) => acc.push(x)); } return acc; }, [])
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (4)
Previous results
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Test case name
Result
reduce
flatMap
flat
dumb
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
**Benchmark Overview** MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark definition measures the performance of three different approaches for flattening an array: `flat`, `flatMap`, and `reduce`. Additionally, there's a "dumb" approach using a loop to concatenate arrays. **Options Compared** The three options being compared are: 1. **`flat()`**: This method creates a new array with all sub-array elements concatenated into it recursively up to the specified depth. 2. **`flatMap(x => x)`**: This is an arrow function that applies `Array.prototype.map()` on each element of the original array, returning a new array with the results. 3. **`reduce((acc, val) => acc.concat(val), [])`**: This method reduces the array to a single value by iteratively concatenating arrays using the provided callback function. **Pros and Cons of Each Approach** 1. **`flat()`**: * Pros: Simple, easy to read, and intuitive. * Cons: Can be slow due to recursive calls, may exceed maximum recursion depth for large arrays. 2. **`flatMap(x => x)`**: * Pros: Efficient by leveraging built-in `map()` functionality, avoids potential stack overflow issues. * Cons: May have higher memory usage compared to other approaches. 3. **`reduce((acc, val) => acc.concat(val), [])`**: * Pros: Can be more efficient than `flat()` for large arrays, as it doesn't create a new array recursively. * Cons: Less intuitive and harder to read due to the callback function. **Library Used** None of the provided approaches rely on any external libraries. They are built-in JavaScript methods or simple loops. **Special JS Feature/Syntax** The `flatMap()` method is a relatively new feature in JavaScript, introduced in ECMAScript 2019 (ES10). It's an array method that applies `Array.prototype.map()` to each element of the original array and returns a new array with the results. The provided benchmark tests its performance. **Other Considerations** * The "dumb" approach using a loop is included for comparison, but it may not be representative of real-world usage. * Browser-specific differences in execution speed may affect the results. * The number of iterations (10,000) and array depth (20) can impact the benchmark results. **Alternatives** If you're interested in exploring alternative approaches or libraries for array flattening, consider: 1. Using `Array.prototype.flat()` with an optional `depth` parameter to control recursion. 2. Leveraging third-party libraries like Lodash (`_flattenDeep()`) or Underscore (`_flatten()`) for more complex flattening scenarios. 3. Exploring alternative data structures, such as tuples or sets, which might offer different performance characteristics. Keep in mind that the `flatMap()` method is a relatively new feature, and its adoption may vary across browsers and JavaScript engines.
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