Benchmark: flatMap vs reduce vs while vs foreach

Script Preparation code:

var n = 1000

Tests:

reduce
[...Array(n).keys()].reduce((acc, cur) => [...acc, ++cur, cur++], [])
while
let res = [], i=0; while(n>i++) res.push(i, i);
foreach
let res = []; Array(n).fill(0).forEach((_,i) => res.push(i+1, i+1))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
while
foreach

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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**Benchmark Overview**

The MeasureThat.net benchmark compares the performance of four different JavaScript iteration methods: `flatMap`, `reduce`, `while`, and `forEach`. The benchmark is designed to test how each method handles a specific use case, where an array of numbers is flattened into another array.

**Options Compared**

1. **flatMap**: A modern JavaScript method that uses the spread operator (`...`) to flatten an array.
2. **reduce**: A classic JavaScript method that uses a callback function to reduce an array to a single value or an array.
3. **while**: A traditional loop construct that uses a while loop to iterate over an array.
4. **forEach**: A modern JavaScript method that uses a callback function to execute an action on each element of an array.

**Pros and Cons**

1. **flatMap**:
	* Pros: Concise, readable, and efficient. It avoids the need for explicit indexing or iteration.
	* Cons: Requires modern browsers to support the spread operator (`...`).
2. **reduce**:
	* Pros: Widely supported, flexible, and can be used for various operations beyond flattening arrays.
	* Cons: Can be less readable than other methods, especially for those unfamiliar with callback functions.
3. **while**:
	* Pros: Traditional loop construct, easy to understand, and widely supported across browsers.
	* Cons: Less concise and more verbose than other methods.
4. **forEach**:
	* Pros: Modern, readable, and efficient. It's a good choice for iterative operations with minimal side effects.
	* Cons: Not as widely supported as `reduce`, especially in older browsers.

**Library/Function Usage**

None of the benchmarked functions rely on external libraries or frameworks. They are all part of the standard JavaScript language.

**Special JS Features/Syntax**

The benchmark uses modern JavaScript features, such as:

1. **Spread operator (`...`)**: Used in `flatMap` to flatten an array.
2. **Arrow functions**: Used in `reduce`, `forEach`, and other places for concise function definitions.
3. **Template literals**: Used in the script preparation code for easy string concatenation.

**Other Alternatives**

For similar use cases, alternative iteration methods might include:

1. **Array.prototype.map()`: While not directly comparable to `flatMap`, it can be used to create a new array with transformed elements.
2. **Array.prototype.forEach.call()**: This method combines the benefits of `forEach` and array iteration, but is less readable than either alone.
3. **Manual indexing**: Using explicit indexing (`i = 0; while (n > i++)`) for iteration, which can be more verbose and error-prone.

Keep in mind that each approach has its trade-offs, and the choice of method depends on factors like code readability, maintainability, performance, and compatibility across different browsers.

Related benchmarks:

flatMap vs reduce vs while vs foreach (version: 0)

Comparing performance of: reduce vs while vs foreach

Created: 5 years ago by: Guest

Jump to the latest result

reduce

while

foreach

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):