Benchmark: Lodash each vs Object.entries.forEach vs for...in

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

var data100 = _.fill(Array(100), 1).reduce((r, v, i) => (r[`k${i}`] = v, r), {});
var data1000 = _.fill(Array(1000), 1).reduce((r, v, i) => (r[`k${i}`] = v, r), {});

Tests:

lodash.each
var sum = 0; _.each(data100, (v, k) => sum+=v)
Object.entries.forEach
var sum = 0; Object.entries(data100).forEach(([v, k]) => sum+=v)
for...in
var sum = 0; for (let k in data100) { sum+=data100[k]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash.each
Object.entries.forEach
for...in

Fastest: N/A

Slowest: N/A

Latest 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 dive into the world of JavaScript microbenchmarks.

**Benchmark Overview**

The provided benchmark tests three different ways to iterate over an object in JavaScript:

1. Lodash's `each` function
2. The `forEach` method on arrays using `Object.entries`
3. A traditional `for...in` loop

Each test case uses the same data structure, an object with 100 or 1000 key-value pairs, initialized using Lodash's `fill` and `reduce` methods.

**Benchmark Definitions**

Let's break down each benchmark definition:

1. **Lodash's `each` function**:
```javascript
var sum = 0;
_.each(data100, (v, k) => sum += v);
```
This test uses Lodash's `each` function to iterate over the object and accumulate the sum of its values.

2. **`Object.entries.forEach`**:
```javascript
var sum = 0;
Object.entries(data100).forEach(([v, k]) => sum += v);
```
This test uses the `Object.entries` method to convert the object into an array of key-value pairs and then iterates over it using the `forEach` method.

3. **Traditional `for...in` loop**:
```javascript
var sum = 0;
for (let k in data100) { sum += data100[k]; }
```
This test uses a traditional `for...in` loop to iterate over the object's properties and accumulate the sum of its values.

**Options Compared**

The three options are compared in terms of their performance, which is measured by the number of executions per second.

* **Lodash's `each` function**: This option relies on Lodash's optimized iteration mechanism, which uses a custom loop to iterate over the array.
* **`Object.entries.forEach`**: This option uses the built-in `Object.entries` method and the `forEach` method on arrays. The performance of this option is likely influenced by the overhead of calling these methods.
* **Traditional `for...in` loop**: This option uses a traditional loop to iterate over the object's properties, which can be slower due to the overhead of the loop and potential issues with property iteration.

**Pros and Cons**

Here are some pros and cons for each option:

1. **Lodash's `each` function**:
	* Pros: Optimized for performance, easy to use.
	* Cons: Requires Lodash library, may not be suitable for all use cases.
2. **`Object.entries.forEach`**:
	* Pros: Easy to use, uses built-in methods.
	* Cons: May have overhead due to method calls, can be slower than custom loops.
3. **Traditional `for...in` loop**:
	* Pros: Simple and easy to understand, no external dependencies.
	* Cons: Can be slower than optimized iteration mechanisms, may not work as expected for certain use cases.

**Library Used**

In this benchmark, Lodash is used as a library to provide an optimized iteration mechanism.

**Special JavaScript Features or Syntax**

There are no special features or syntax used in this benchmark that would require specific knowledge of JavaScript. The code snippets provided are straightforward and easy to understand.

**Alternatives**

If you need to iterate over objects in JavaScript, here are some alternative approaches:

* Use a custom loop with `in` operator: `for (let k in data100) { sum += data100[k]; }`
* Use a library like Lo-Dash or Lodash alternative (e.g., Ramda)
* Use modern JavaScript features like `for...of` loop or `Array.prototype.forEach`

Keep in mind that the performance of these alternatives may vary depending on the specific use case and requirements.

Related benchmarks:

Lodash each vs Object.entries.forEach vs for...in (version: 0)

Comparing performance of: lodash.each vs Object.entries.forEach vs for...in

Created: 5 years ago by: Registered User

Jump to the latest result

lodash.each

Object.entries.forEach

for...in

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):