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mapvsflatmap
(version: 1)
Comparing performance of:
map vs flatmap
Created:
3 years ago
by:
Registered User
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Script Preparation code:
var arr = []; var i = 0; while (i <= 1E5) arr[i] = i++;
Tests:
map
arr.map(x => x/100)
flatmap
arr.flatMap(x => x % 3 ? x/100 : [])
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
map
flatmap
Fastest:
N/A
Slowest:
N/A
Latest run results:
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the benchmark and explain what's being tested. **Benchmark Overview** The benchmark is designed to compare the performance of two JavaScript functions: `map()` and `flatMap()`. Both functions are used to transform an array, but they differ in how they handle nested arrays or null/undefined values. **Benchmark Definition JSON** The benchmark definition json contains: * `Name`: a unique name for the benchmark ("mapvsflatmap") * `Description`: an empty string (no description provided) * `Script Preparation Code`: a script that initializes an array `arr` and fills it with numbers from 0 to 100,000 using a `while` loop. * `Html Preparation Code`: an empty string (no HTML code is required) The purpose of this preparation code is to create a large input array (`arr`) for the benchmark. The script will be executed once before running the actual benchmark. **Individual Test Cases** There are two individual test cases: 1. **map** * `Benchmark Definition`: `arr.map(x => x/100)` * Purpose: Apply the function `(x) => x / 100` to each element of the array `arr`. 2. **flatmap** * `Benchmark Definition`: `arr.flatMap(x => x % 3 ? x/100 : [])` * Purpose: Apply the function `(x) => (x % 3 ? x / 100 : [])` to each element of the array `arr`. This function will return an empty array if the remainder of dividing the current number by 3 is 0, effectively filtering out those numbers. **Pros and Cons** * **map()**: Pros: + More straightforward and intuitive API. + Typically faster than flatMap because it doesn't have to create a new array with filtered elements. * Cons: + Can be slower if the input array has many nested arrays or null/undefined values, as it will still iterate over those elements. * **flatMap()**: Pros: + More flexible and powerful API for handling nested arrays or filtering out certain elements. + Can be faster than map() in some cases because it allows the engine to optimize away unnecessary array creations. * Cons: + Less intuitive API, which can lead to mistakes or unexpected behavior. **Library and Special JS Features** No libraries are explicitly mentioned in this benchmark. However, JavaScript engines like V8 (used by Chrome) have various optimizations and internal APIs that can influence performance. One notable feature is the use of `const` and `let` declarations for variable assignments (`var arr = [];`). This syntax is supported by modern JavaScript engines, but older engines might not support it or require explicit function declaration for variables. **Other Alternatives** For a more comprehensive comparison, other alternatives could be: * **filter()**: Instead of flatMap(), using filter() with an arrow function to create a new array with filtered elements would provide similar performance characteristics. * **forEach() + Array.prototype.slice()**: Using forEach() and slicing the resulting array after filtering might also provide comparable performance. However, these alternatives are not part of the original benchmark definition, so they're not being directly compared here.
Related benchmarks:
flatMap() vs map().flat()
flatMap vs mapFlat
.flatMap() vs .map()
1htrghdr
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