Benchmark: lodash forEach vs for i loop with length cached vs Array#forEach vs Array#map

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/lodash/4.16.0/lodash.min.js"></script>

Script Preparation code:

var values = [{a: 30310}, {b: 100303}, {c: 3040494}]

Tests:

lodash.forEach
var count = 0; _.forEach(values, function(v,i) { if (v.a != null) { count++; } })
native
var count = 0; for (var i = 0, len = values.length; i < len; i++) { if (values[i].a != null) { count++; } }
Array#forEach
var count = 0; values.forEach(function(v,i) { if (v.a != null) { count++; } })
Array#map
var count = 0; values.map(function(v,i) { if (v.a != null) { count++; } })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash.forEach
native
Array#forEach
Array#map

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 benchmark and explain what is being tested.

**Benchmark Overview**

The benchmark compares the performance of three different approaches to iterate over an array in JavaScript:

1. `lodash.forEach`
2. A native `for` loop with length caching (`native`)
3. The `Array#forEach` method
4. The `Array#map` method

**Options Being Compared**

* `_.forEach(values, function(v,i) { ... })`: This is a custom implementation of the `forEach` method using Lodash.
* `for (var i = 0, len = values.length; i < len; i++) { ... }`: This is a traditional `for` loop that iterates over the array by accessing its length property.
* `values.forEach(function(v,i) { ... })`: This uses the built-in `forEach` method of JavaScript arrays.
* `values.map(function(v,i) { ... })`: This uses the built-in `map` method of JavaScript arrays.

**Pros and Cons of Each Approach**

1. **_forEach**: Lodash's custom implementation:
	* Pros: It may have additional features like callback function signature handling, which can be useful in certain situations.
	* Cons: It introduces an external library dependency, which may increase the overhead of the benchmark.
2. **Native For Loop with Length Caching**:
	* Pros: This is a lightweight, native implementation that doesn't require any external libraries.
	* Cons: It requires manual indexing and length checking, which can be error-prone and slower for large arrays.
3. **Array#forEach**: Built-in JavaScript array method:
	* Pros: It's implemented in C++ by the V8 engine, making it very fast and efficient.
	* Cons: It doesn't provide direct access to the iteration index `i`, which may be useful in certain situations.
4. **Array#map**:
	* Pros: Like `Array#forEach`, it's a built-in JavaScript array method that's implemented in C++ by the V8 engine.
	* Cons: It's designed for transformation and return values, not just iteration.

**Library - Lodash**

Lodash is a popular utility library for JavaScript that provides various helper functions, including `forEach`. The implementation used in this benchmark is specifically designed to test the performance of the `forEach` method.

**Special JS Feature/Syntax**

None are mentioned in the provided information. However, note that modern JavaScript has features like async/await, classes, and modules (ES6+), which might be relevant for more complex benchmarks.

**Other Alternatives**

For array iteration, you could also consider using other libraries or methods, such as:

* `Array.prototype.reduce()`
* `Array.prototype.every()`
* `Array.prototype.some()`

However, these alternatives may not provide the same level of performance as the native `forEach` method or Lodash's implementation.

Keep in mind that this benchmark is specific to JavaScript and the V8 engine used by Chrome. The results might vary depending on the browser and JavaScript engine used.

Related benchmarks:

lodash forEach vs for i loop with length cached vs Array#forEach vs Array#map (version: 0)

Comparing performance of: lodash.forEach vs native vs Array#forEach vs Array#map

Created: 6 years ago by: Guest

Jump to the latest result

lodash.forEach

native

Array#forEach

Array#map

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):