Benchmark: Lodash takeRight vs slice

HTML Preparation code:

<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js'></script>

Script Preparation code:

function getRandomInt(max) {
  return Math.floor(Math.random() * Math.floor(max));
}

var arr = [];
for(var i = 0; i < 100000; i++){
  arr.push({value:getRandomInt(100)});
}

Tests:

_.takeRight
_.takeRight(arr, 3);
array.prototype.slice
arr.slice(arr, -3);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
_.takeRight
array.prototype.slice

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 27 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
_.takeRight	7160898.5 Ops/sec
array.prototype.slice	444.9 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what's being tested, compared, and the pros/cons of each approach.

**Benchmark Definition**

The benchmark is designed to compare two approaches for taking the last 3 elements from an array:

1. **Lodash `takeRight`**: A function that takes an array and a number as arguments, returning a new array containing the elements from the end up to but not including the specified length.
2. **Array.prototype.slice** (using negative indexing): A method that creates a shallow copy of a portion of an array, with a start index of 0, an end index equal to the current length, and an optional step value.

**Script Preparation Code**

The script preparation code generates a large array (`arr`) containing 100,000 objects with random integer values between 0 and 100. This array serves as the input for both benchmarked functions.

**Html Preparation Code**

The HTML preparation code includes a reference to Lodash version 4.17.21, which is used by the `takeRight` function.

**Individual Test Cases**

There are two test cases:

1. **Lodash `takeRight`**: Measures the execution time of the `_.takeRight(arr, 3)` function.
2. **Array.prototype.slice**: Measures the execution time of the `arr.slice(arr, -3)` expression (using negative indexing).

**Comparison**

The benchmark compares the performance of these two approaches:

1. **Lodash `takeRight`**: Pros:
	* Simplified and optimized implementation
	* Uses a library that provides additional utility functions
	* May be faster due to its internal optimizations
2. **Array.prototype.slice**: Pros:
	* Native JavaScript implementation, potentially more efficient
	* Doesn't rely on an external library
	* Can be optimized by the browser's JIT compiler

**Cons**

1. **Lodash `takeRight`**:
	* Requires including the Lodash library, which adds overhead
	* May have additional dependencies or conflicts
2. **Array.prototype.slice**:
	* May not be as efficient due to the need for manual indexing and length calculations
	* Can lead to slower performance on large arrays

**Library: Lodash**

Lodash is a popular JavaScript utility library that provides a wide range of functions, including `takeRight`. It's designed to simplify common tasks and provide a consistent interface across different programming languages. The use of Lodash in this benchmark allows developers to easily switch between approaches without having to implement the logic themselves.

**Special JS Feature: Arrow Functions**

The script preparation code uses arrow functions (`() => { ... }`) to create the random integer generator function. This feature was introduced in ECMAScript 2015 (ES6) and provides a concise syntax for defining small, one-time use functions.

Other alternatives to these approaches:

* **Using `Array.prototype.slice` with positive indexing**: Instead of using negative indexing, you can use `arr.slice(0, arr.length - 3)` to achieve the same result.
* **Implementing custom `takeRight` function**: You could write your own implementation of `takeRight` using native JavaScript functions and loops.

In conclusion, this benchmark provides a useful comparison between two approaches for taking the last few elements from an array: Lodash's optimized `takeRight` function versus the native `Array.prototype.slice` method with negative indexing. The results will help developers understand the performance implications of each approach in their own codebase.

Related benchmarks:

Lodash takeRight vs slice (version: 0)

Comparing performance of: _.takeRight vs array.prototype.slice

Created: 3 years ago by: Guest

Jump to the latest result

_.takeRight

array.prototype.slice

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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