Benchmark: Native JS: reduce vs join

Script Preparation code:

var array = [];
var index = 0;
while (index < 1000) {
  array.push("" + index++);
}

Tests:

using reduce function
array.reduce(function (a,b) { return a.concat(b); }, "");
using join function
array.join("");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
using reduce function
using join function

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.69 Safari/537.36

Browser/OS: Chrome 95 on Windows

View result in a separate tab

Test name	Executions per second
using reduce function	93374.6 Ops/sec
using join function	42167.6 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark compares two approaches for concatenating elements in an array: using the `reduce()` method and using the `join()` method.

**Options Compared**

There are two options compared:

1. **Using `reduce()` method**: This approach uses the `reduce()` method to concatenate all elements in the array. The `reduce()` method applies a callback function to each element in the array, reducing it to a single value.
2. **Using `join()` method**: This approach uses the `join()` method to concatenate all elements in the array. The `join()` method takes an iterable of values and concatenates them into a string.

**Pros and Cons**

* **Using `reduce()` method:**
	+ Pros:
		- Can be more flexible, as it allows for custom callback functions.
		- Can handle arrays with multiple types of elements (e.g., strings, numbers).
	+ Cons:
		- Can be slower than the `join()` method due to the overhead of function calls and iteration.
* **Using `join()` method:**
	+ Pros:
		- Typically faster than the `reduce()` method, as it's a built-in method optimized for string concatenation.
		- Simpler to use, especially when dealing with arrays of strings.
	+ Cons:
		- Limited flexibility, as it requires specific input formatting (e.g., all elements must be strings).

**Library and Special JS Features**

There is no explicit library mentioned in the benchmark definition. However, `reduce()` and `join()` are built-in methods in JavaScript.

No special JavaScript features or syntax are used in this benchmark.

**Other Alternatives**

If you need to concatenate arrays, other alternatives might include:

1. **Looping**: Using a traditional loop (e.g., `for` or `while`) to iterate through the array and append elements.
2. **Array.prototype.forEach()**: Using the `forEach()` method to iterate through the array and execute a callback function for each element.

However, these alternatives might not be as efficient or readable as using built-in methods like `reduce()` or `join()`.

Related benchmarks:

Native JS: reduce vs join (version: 0)

compare approach for join element of array

Comparing performance of: using reduce function vs using join function

Created: 4 years ago by: Registered User

Jump to the latest result

using reduce function

using join function

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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