Benchmark: foreach vs map1 - MeasureThat.net

Script Preparation code:

var values = new Array(10000);
for (var i = 0; i < values.length; i++) values[i]=i;

Tests:

foreach
var sum = 0; values.forEach(v => sum += v );
map
var sum = 0; values.map(v => sum += v );
for of transpiled
var sum = 0; for (var _i = 0, values_1 = values; _i < values_1.length; _i++) { var v = values_1[_i]; sum += v; }
reduce
var sum = values.reduce((s,v) => sum += v, 0);
for of
var sum = 0; for (var v of values) sum += v;
for of transpiled1
var sum = 0; for (var _i = 0; _i < values.length; _i++) { var v = values[_i]; sum += v; }
for of transpiled2
var sum = 0; for (var _i = 0; _i < values.length; _i++) { var v = values[_i]; sum += values[_i]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
map
for of transpiled
reduce
for of
for of transpiled1
for of transpiled2

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases.

**Benchmark Definition:**

The benchmark is designed to compare different approaches for iterating over an array in JavaScript. The `foreach`, `map`, and `for...of` constructs are compared, as well as two transpiled versions of the `for...of` construct (`for...of transpiled` and `for...of transpiled1`). Additionally, a `reduce` method is used to calculate the sum of an array.

**Options being compared:**

1. `foreach`: Iterates over the array using a traditional for loop with indexing.
2. `map`: Returns a new array with the results of applying a provided function to each element in the original array.
3. `for...of`: A modern, iterator-based approach to iterating over arrays and other iterable objects.
4. Two transpiled versions of `for...of`: These versions are identical, but may be compiled differently by the JavaScript engine or used in different contexts.

**Pros and Cons:**

1. `foreach`:
	* Pros: Simple, well-established, and widely supported.
	* Cons: Can be slower due to the use of indexing and potentially creating intermediate arrays.
2. `map`:
	* Pros: Creates a new array with transformed values, can be useful for filtering or transforming data.
	* Cons: Can be slower than other approaches, as it creates a new array and performs additional operations.
3. `for...of`:
	* Pros: Modern, efficient, and easy to read. It's also a built-in part of the language, making it more portable and accessible.
	* Cons: Requires knowledge of iterators and may not be supported in older browsers or environments.
4. Transpiled versions of `for...of`:
	* These versions are identical but compiled differently, potentially affecting performance.

**Other considerations:**

* The use of transpiled versions of `for...of` may indicate a desire to support older browsers or environments that don't natively support the modern construct.
* The inclusion of both `for...of` and its transpiled versions suggests an interest in measuring the overhead of different compilation strategies.

**Library usage:**

None mentioned in this benchmark definition.

**Special JS feature or syntax:**

The use of `map`, `reduce`, and `for...of` is a standard part of modern JavaScript. The `for...of` construct, while widely supported, may require knowledge of iterators to work correctly.

Other alternatives for iterating over arrays could include:

* `forEach`: A similar approach to the traditional for loop.
* `filter()`, `slice()`, and other array methods that can be used to manipulate data without iteration.
* Custom loops or recursive functions.
* Other modern approaches like WebAssembly-based iterators or experimental constructs like `for...in` (note that this is not a replacement for `for...of`).

Keep in mind that the choice of iteration method depends on the specific use case, performance requirements, and desired outcome.

Related benchmarks:

foreach vs map1 (version: 0)

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Comparing performance of: foreach vs map vs for of transpiled vs reduce vs for of vs for of transpiled1 vs for of transpiled2

Created: 3 years ago by: Guest

Jump to the latest result

foreach

map

for of transpiled

reduce

for of

for of transpiled1

for of transpiled2

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):