Benchmark: SUM with forEach vs lodash.map vs map fix

HTML Preparation code:

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

Tests:

reduce
let posts = [ {id: 1, upVotes: 2}, {id: 2, upVotes: 18}, {id: 3, upVotes: 1}, {id: 4, upVotes: 30}, {id: 5, upVotes: 50} ]; var sum = 0 sum = posts.reduce((s, p)=> s+=p.upVotes,0);
Lodash map
let posts = [ {id: 1, upVotes: 2}, {id: 2, upVotes: 18}, {id: 3, upVotes: 1}, {id: 4, upVotes: 30}, {id: 5, upVotes: 50} ]; var sum = 0 sum = _.map(posts, (element, i) => sum += element.upVotes)
map
let posts = [ {id: 1, upVotes: 2}, {id: 2, upVotes: 18}, {id: 3, upVotes: 1}, {id: 4, upVotes: 30}, {id: 5, upVotes: 50} ]; var sum = 0 sum = posts.map(element => { sum += element.upVotes; });
forEach
let posts = [ {id: 1, upVotes: 2}, {id: 2, upVotes: 18}, {id: 3, upVotes: 1}, {id: 4, upVotes: 30}, {id: 5, upVotes: 50} ]; var sum = 0 sum = posts.forEach(element => { sum += element.upVotes; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
reduce
Lodash map
map
forEach

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

**Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks, comparing the performance of different approaches to solve a specific problem.

**Benchmark Definition JSON**

The provided JSON represents a benchmark named "SUM with forEach vs lodash.map vs map fix". The benchmark consists of four test cases:

1. `reduce`
2. `Lodash map`
3. `map` (without Lodash)
4. `forEach`

Each test case uses an array of objects (`posts`) to calculate the sum of the `upVotes` property.

**Test Cases**

Let's break down each test case:

### 1. `reduce`

The `reduce` method applies a user-supplied function to each element in the array, accumulating a result. In this case, the accumulator (`sum`) is initialized to 0 and updated with the sum of the `upVotes` property for each object in the array.

Pros: Efficient use of memory, no additional iterations required.

Cons: Can be slower than other methods if the user-supplied function is complex or has many iterations.

**Lodash `map`**

The `Lodash map` method applies a callback function to each element in the array and returns an array of results. In this case, the callback function adds the sum of the `upVotes` property to the accumulator (`sum`) for each object in the array.

Pros: Convenient and concise way to perform iterations, especially with Lodash's extensive library functions.

Cons: Creates a new array with intermediate results, which can be slower than other methods.

**Lodash `map` (with fix)**

This test case uses a modified version of the `Lodash map` method that avoids creating an additional array. Instead, it directly updates the accumulator (`sum`) for each object in the array.

Pros: Similar to Lodash's original implementation, but without creating an intermediate array.

Cons: May be slower than the original Lodash `map` implementation due to the overhead of updating the accumulator manually.

**`forEach`**

The `forEach` method applies a callback function to each element in the array and returns no value. In this case, the callback function adds the sum of the `upVotes` property to the accumulator (`sum`) for each object in the array.

Pros: Convenient way to perform iterations without creating an intermediate array.

Cons: May be slower than other methods due to the overhead of calling a separate method for each iteration.

**Libraries and Features**

* Lodash is a popular JavaScript library that provides utility functions, including `map` and other iteration helpers.
* No specific JavaScript features or syntax are used in these test cases.

Latest run results:

Run details: (Test run date: 2 days ago)

User agent: Mozilla/5.0 (iPad; CPU OS 17_6_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/131.0.6778.73 Mobile/15E148 Safari/604.1

Browser/OS: Chrome Mobile iOS 131 on iOS 17.6.1

View result in a separate tab

Test name	Executions per second
reduce	15209647.0 Ops/sec
Lodash map	4105505.0 Ops/sec
map	8542531.0 Ops/sec
forEach	11225934.0 Ops/sec

Related benchmarks:

SUM with forEach vs lodash.map vs map fix (version: 0)

Comparing performance of: reduce vs Lodash map vs map vs forEach

Created: 5 years ago by: Guest

Jump to the latest result

reduce

Lodash map

map

forEach

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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