Benchmark: String concatenation vs array join #2

Tests:

String concatentation
let str = ""; for (let i = 0; i < 1000; i++) { str += "String concatenation. "; }
Array join
let arr = []; for (let i = 0; i < 1000; i++) { arr[i] = "String concatenation. "; } str = arr.join("");
Array join (w/ push)
let arr = []; for (let i = 0; i < 1000; i++) { arr.push("String concatenation. "); } str = arr.join("");

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

String concatentation

984K/s

Array join (w/ push)

127K/s

Array join

123K/s

Fastest: String concatentation (8.0x faster)

View exact numbers

✓ String concatentation: 983,851 ops/sec
• Array join (w/ push): 126,584 ops/sec
• Array join: 122,636 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String concatentation
Array join
Array join (w/ push)

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:153.0) Gecko/20100101 Firefox/153.0

Browser/OS: Firefox 153 on Linux

View result in a separate tab

String concatentation

258K/s

Array join (w/ push)

108K/s

Array join

105K/s

View exact numbers

Test name	Executions per second
✓ String concatentation	258,311 Ops/sec
Array join (w/ push)	107,659 Ops/sec
Array join	105,013 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark is testing two approaches for string concatenation in JavaScript:

1. **String Concatenation**: Directly appending strings to a variable using the `+` operator or string interpolation (`"Hello, " + name`).
2. **Array Join**: Using the `join()` method on an array of strings.

**Options Compared**

The benchmark is comparing three variations of array join:

1. **Array Join (w/ push)**: Creating an empty array and pushing elements onto it before joining using the `push()` method.
2. **Array Join**: Creating an empty array and then joining its elements using the `join()` method.

**Pros and Cons**

* **String Concatenation**:
	+ Pros: Simple, widely supported, and easy to read.
	+ Cons: Can lead to performance issues due to the creation of temporary strings and the overhead of string concatenation.
* **Array Join (w/ push)**:
	+ Pros: Can be faster than traditional array join for large arrays because it avoids creating intermediate strings.
	+ Cons: Requires more memory allocation and can lead to slower performance for small arrays.
* **Array Join**:
	+ Pros: More efficient than traditional array join for large arrays, as it avoids creating intermediate strings.
	+ Cons: Can be slower than `push()`-based approach for small arrays.

**Special JS Feature**

None mentioned in this benchmark.

**Library and Purpose**

The `join()` method is a built-in JavaScript method that concatenates all elements of an array into a single string. The purpose is to provide a convenient way to concatenate strings in arrays without having to use the `+` operator or string interpolation.

**Other Alternatives**

For larger projects, you might want to consider using libraries like [Lodash](https://lodash.com/) which provides a more efficient and concise way of concatenating arrays using its `join()` function.

Keep in mind that the performance differences between these approaches are generally significant only for large datasets or performance-critical code. For smaller projects, readability and simplicity might be more important considerations than micro-optimizations.

In this benchmark, the goal is likely to demonstrate the performance difference between these three methods, which can help developers make informed decisions about their coding practices.

String concatenation vs array join #2 (version: 0)

Comparing performance of: `String concatentation vs Array join vs Array join (w/ push)`

Created: 5 years ago by: Guest

Go to the latest result

String concatentation

Array join

Array join (w/ push)

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

String concatenation vs array join #2 (version: 0)

Comparing performance of: String concatentation vs Array join vs Array join (w/ push)

Created: 5 years ago by: Guest

Go to the latest result

String concatentation

Array join

Array join (w/ push)

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

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