Benchmark: array.push vs array.map

Script Preparation code:

var strs = Array.from(new Array(100000)).map(() => 'String concat. ')
var result = []

Tests:

array.push
for (let i = 0; i < strs.length; i++) { result.push(`${strs[i]}_ok_${strs[i] * 532}`) }
array.map
result = strs.map((a) => `${strs[i]}_ok_${strs[i] * 532}`)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.push
array.map

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Purpose**

The benchmark measures the performance difference between using `Array.prototype.push()` versus `Array.prototype.map()` to concatenate strings in an array.

**Options Compared**

Two options are compared:

1. `array.push`: This method appends a new element to the end of the array and returns the length of the updated array.
2. `array.map()`: This method creates a new array with the results of applying a provided function to each element in the original array.

**Pros and Cons**

Here are some pros and cons for each approach:

* `array.push`:
	+ Pros: Simple, widely supported, and can be more efficient for small arrays.
	+ Cons: Creates a new array object, which can lead to increased memory allocation and garbage collection overhead. Can also be slower due to the need to resize the array.
* `array.map()`: 
	+ Pros: More concise and expressive than `push()`, especially when working with larger datasets. Returns an entirely new array, reducing side effects on the original data.
	+ Cons: Creates a new array object, which can lead to increased memory allocation and garbage collection overhead. Can also be slower due to the need to create and copy the new array.

**Library Usage**

There is no specific library used in this benchmark. However, `Array.prototype.map()` uses the built-in JavaScript method for creating arrays with transformed data.

**Special JS Feature/Syntax**

This benchmark does not use any special JavaScript features or syntax beyond what's required for basic arithmetic operations and string concatenation.

**Alternatives**

Other alternatives for array concatenation could include:

* Using a loop with `push()` instead of `map()`: `for (let i = 0; i < strs.length; i++) { result.push(strs[i] + '_ok_' + strs[i] * 532) }`
* Using other methods like `Array.prototype.reduce()`, which can be more efficient for large arrays.

In conclusion, the benchmark provides a clear comparison between two common methods for array concatenation in JavaScript. Understanding the trade-offs and pros/cons of each approach can help developers make informed decisions about performance-critical code paths.

Latest run results:

Run details: (Test run date: 6 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:125.0) Gecko/20100101 Firefox/125.0

Browser/OS: Firefox 125 on Linux

View result in a separate tab

Test name	Executions per second
array.push	89.1 Ops/sec
array.map	107.4 Ops/sec

Related benchmarks:

array.push vs array.map (version: 0)

Comparing performance of: array.push vs array.map

Created: 6 months ago by: Guest

Jump to the latest result

array.push

array.map

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):