Benchmark: String concatenation vs array join preciselarge

Script Preparation code:

var str = "";
var i;
var sArr = new Array(1000000).fill("String concatenation. ")

Tests:

String concatentation
for (i = 1000000; i > 0; i--) { str += "String concatenation. "; }
Array join
str = sArr.join("");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
String concatentation
Array join

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36 Edg/132.0.0.0

Browser/OS: Chrome 132 on Windows

View result in a separate tab

Test name	Executions per second
String concatentation	0.0 Ops/sec
Array join	81.8 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The test compares two approaches to concatenate strings: `string concatenation` (also known as `+=`) and `array join`. The goal is to determine which method is more efficient for large numbers of concatenations.

**Options Compared**

There are two options compared:

1. **String Concatenation**: This approach uses the `+=` operator to append a string to an existing string.
2. **Array Join**: This approach uses the `join()` method on an array of strings, which concatenates them into a single string.

**Pros and Cons**

**String Concatenation**

Pros:

* Easy to implement and understand
* No additional data structures are required

Cons:

* Can be slower due to the overhead of creating temporary objects and performing operations on them
* May cause memory fragmentation if not used carefully

**Array Join**

Pros:

* Often faster than string concatenation, especially for large datasets
* Reduces the risk of memory fragmentation by avoiding manual string concatenation

Cons:

* Requires additional data structures (arrays) to store intermediate results
* Can be less intuitive and harder to understand for some developers

In general, array join is a more efficient approach when dealing with large datasets, but it may require more setup and understanding for new developers.

**Library Usage**

The test uses the `Array.prototype.join()` method, which is a built-in JavaScript function that concatenates all elements in an array into a single string. The purpose of this library is to provide a convenient way to concatenate arrays of strings without having to manually iterate over each element.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntax used in this benchmark. Both approaches rely on standard JavaScript language constructs.

**Other Alternatives**

In addition to the two options compared, there are other alternatives for string concatenation:

* **Template literals**: Introduced in ECMAScript 2015 (ES6), template literals allow you to embed expressions inside string literals using backticks (`).
* **`String.prototype.repeat()` method**: Introduced in ECMAScript 2015 (ES6), the `repeat()` method allows you to repeat a string multiple times.

These alternatives can provide even more efficient ways to concatenate strings, but may require more knowledge of advanced JavaScript features.

Overall, the benchmark provides a useful comparison between two common approaches to string concatenation, highlighting the benefits and drawbacks of each.

Related benchmarks:

String concatenation vs array join preciselarge (version: 0)

Comparing performance of: String concatentation vs Array join

Created: 3 years ago by: Guest

Jump to the latest result

String concatentation

Array join

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):