Benchmark: concat vs lodash.concat vs. push.apply vs. spread operator vs.test

HTML Preparation code:

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

Script Preparation code:

var arr1 = ["what", "is", "this"];
var arr2 = ["this", "is", "a", "test", "hello", "how", "are", "you", "today"];

Tests:

Array.prototype.concat
var result = arr1.concat(arr2);
Array.prototype.push.apply()
Array.prototype.push.apply(arr1, arr2);
cached for + push
for (var i = 0, l = arr2.length; i < l; i++) { arr1.push(arr2[i]) }
naive
for (var i = 0, l = arr2.length; i < l; i++) { arr1[i] = arr2[i] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
Array.prototype.push.apply()
cached for + push
naive

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0.3 Safari/605.1.15

Browser/OS: Safari 14 on Mac OS X 10.15.6

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	6683270.0 Ops/sec
Array.prototype.push.apply()	3494000.8 Ops/sec
cached for + push	969211.6 Ops/sec
naive	1181909.1 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 benchmark and its test cases.

**Benchmark Overview**

The benchmark is designed to compare the performance of different approaches for concatenating two arrays in JavaScript. The options being compared are:

1. `Array.prototype.concat()`
2. `Array.prototype.push.apply()`
3. "cached for + push" (a custom implementation)
4. "naive" (a simple, straightforward implementation)

**Library Used: Lodash**

The benchmark includes the Lodash library, which is a utility library that provides various functions for tasks such as string manipulation, array manipulation, and more. In this case, the `lodash.concat` function is used.

**Test Cases**

Each test case represents a different approach to concatenating two arrays:

1. **Array.prototype.concat()**: This is the built-in method in JavaScript's Array prototype that concatenates two arrays.
2. **Array.prototype.push.apply()**: This method applies an array to another array using `push()` in a loop.
3. **Cached for + push**: This is a custom implementation that uses caching (not explicitly shown in the benchmark) and pushes elements onto the first array using `push()`.
4. **Naive**: This is a simple, straightforward implementation that iterates over the second array and pushes each element onto the first array.

**Pros and Cons**

Here are some pros and cons of each approach:

1. **Array.prototype.concat()**:
	* Pros: concise, efficient
	* Cons: may not be suitable for very large arrays due to the overhead of creating a new array object.
2. **Array.prototype.push.apply()**:
	* Pros: can handle very large arrays efficiently
	* Cons: more verbose and less readable than `concat()`.
3. **Cached for + push**:
	* Pros: potentially faster than `concat()` by avoiding the overhead of creating a new array object, and can be customized to cache specific elements.
	* Cons: requires manual caching and implementation details, which can make it harder to understand and maintain.
4. **Naive**:
	* Pros: easy to understand and implement
	* Cons: may not be as efficient as `concat()` or the custom implementation.

**Other Considerations**

When choosing an approach for concatenating arrays in JavaScript, consider factors such as:

* Performance: If you need to handle very large arrays, one of the more optimized approaches (e.g., `push.apply()`) might be a better choice.
* Readability: If readability is important, the concise and straightforward approach using `concat()` or the naive implementation might be a better fit.
* Customization: If you need to customize the concatenation process for specific use cases, the cached for + push approach could provide more flexibility.

**Alternatives**

Other alternatives for concatenating arrays in JavaScript include:

1. Using the spread operator (`[...arr1, ...arr2]`)
2. Using `Array.prototype.reduce()` with an initial value of the first array
3. Using a library like Lodash's `concat` function or other utility libraries that provide optimized string and array manipulation functions.

These alternatives can offer different trade-offs in terms of performance, readability, and customization options compared to the approaches tested in this benchmark.

Related benchmarks:

concat vs lodash.concat vs. push.apply vs. spread operator vs.test (version: 0)

Comparing performance of: Array.prototype.concat vs Array.prototype.push.apply() vs cached for + push vs naive

Created: 3 years ago by: Guest

Jump to the latest result

Array.prototype.concat

Array.prototype.push.apply()

cached for + push

naive

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):