Benchmark: string literal vs array join

Script Preparation code:

var arr = Array(50000)
  .fill(1)
  .map(() => 'A' + Math.ceil(Math.random() * 100));

Tests:

array.join
var res=arr.join('; ');
string literal
var finalString2 = arr.reduce((res, item) => { return `${res}; ${item}`; }, '');
string concatenation
var finalString3 = arr.reduce((res, item) => { return res + '; ' + item; }, '');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.join
string literal
string concatenation

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
array.join	490.2 Ops/sec
string literal	734.2 Ops/sec
string concatenation	904.7 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 benchmark and its test cases.

**What is being tested?**

The benchmark measures the performance of different approaches to concatenate strings in JavaScript:

1. `string literal` (using template literals or string concatenation with the `+` operator)
2. `array.join` (using the `join()` method on an array of strings)
3. `string concatenation` (using the `+` operator, similar to `string literal`, but without using template literals)

**Options compared**

Each test case compares two or more approaches to concatenate strings. The main options being tested are:

* `array.join`: uses the `join()` method on an array of strings
* `string literal` (template literals or string concatenation with the `+` operator)
* `string concatenation` (using the `+` operator, similar to `string literal`, but without using template literals)

**Pros and cons of each approach**

Here's a brief summary:

* `array.join`:
	+ Pros: efficient, as it uses a built-in method that can handle large arrays
	+ Cons: may be slower for small arrays or strings due to the overhead of the `join()` method
* `string literal` (template literals):
	+ Pros: readable and concise, with no need for explicit concatenation
	+ Cons: may not be supported in older browsers or environments that don't understand template literals
* `string concatenation`:
	+ Pros: familiar and widely supported, as it's the most common way to concatenate strings in JavaScript
	+ Cons: can lead to performance issues if done excessively (e.g., many explicit concatenations)

**Library usage**

There is no library explicitly mentioned in the benchmark code. However, template literals are a built-in feature of modern JavaScript engines.

**Special JS features or syntax**

* Template literals (used in `string literal`) were introduced in ECMAScript 2015 (ES6) and provide a concise way to concatenate strings with expressions.
* The `join()` method on arrays is also a built-in feature, introduced in ECMAScript 2009 (ES5).

**Other alternatives**

If you're looking for alternative approaches to concatenate strings, here are some examples:

* Using a loop: `for (var i = 0; i < arr.length; i++) { output += arr[i]; }`
* Using a string builder library (e.g., `string-pump` or `lodash-string`)
* Using a regex to concatenate strings (although this is generally not recommended)

Keep in mind that these alternatives may have different performance characteristics and trade-offs compared to the approaches tested in the benchmark.

Related benchmarks:

string literal vs array join (version: 9)

Comparing performance of: array.join vs string literal vs string concatenation

Created: 5 years ago by: Registered User

Jump to the latest result

array.join

string literal

string concatenation

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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