Benchmark: ES6 spread operator vs. Array.prototype.reduce()

Script Preparation code:

var myArray = [27, 11, 46, 64, 62, 42, 5, 9];

Tests:

Spread operator
Math.max(...myArray);
Array.prototype.reduce()
myArray.reduce((a, b) => Math.max(a, b))
Array.prototype.reduce() without arrow function
myArray.reduce(Math.max)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread operator
Array.prototype.reduce()
Array.prototype.reduce() without arrow function

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's dive into the provided benchmarking setup.

**Benchmark Definition**

The benchmark is designed to test two different approaches for finding the maximum value in an array: using the spread operator (`...`) and `Array.prototype.reduce()`. The test case uses JavaScript, which allows us to explore various techniques for achieving the same result.

**Options Compared**

In this benchmark:

1. **Spread Operator**: `Math.max(...myArray)` uses the spread operator to pass each element of the array as separate arguments to `Math.max()`.
2. **`Array.prototype.reduce()` with Arrow Function**: `myArray.reduce((a, b) => Math.max(a, b))` employs the `reduce()` method, which iterates over the array and applies a callback function (an arrow function in this case) to each element.
3. **`Array.prototype.reduce()` without Arrow Function**: `myArray.reduce(Math.max)` uses the `reduce()` method with an ordinary function (`Math.max`) as the callback.

**Pros and Cons of Each Approach**

1. **Spread Operator**
	* Pros:
		+ Concise syntax
		+ Expresses intent directly
	* Cons:
		+ Performance overhead due to creating new arrays (even if only one element is passed)
		+ May not be as readable for complex expressions
2. **`Array.prototype.reduce()` with Arrow Function**
	* Pros:
		+ More efficient, as it avoids array creation and uses a single callback function iteration
		+ Can lead to more readable code, especially when combined with other functions or objects
	* Cons:
		+ May be less intuitive for those not familiar with arrow functions
3. **`Array.prototype.reduce()` without Arrow Function**
	* Pros: None explicitly mentioned in the benchmark.
	* Cons: This approach has a performance overhead due to creating an additional function object (`Math.max`) as the callback.

**Library Usage**

The `reduce()` method is a part of the JavaScript Array prototype and does not rely on any external libraries. However, if you consider `Math.max()`, it's part of the JavaScript Math library, but its usage in this benchmark doesn't require importing or referencing external libraries explicitly, as it's an integral part of the standard JavaScript API.

**Special JS Features/Syntax**

In this benchmark:

* **Arrow Functions**: Used in the second test case (`myArray.reduce((a, b) => Math.max(a, b))`) to define a concise and readable callback function.
* No other special features or syntax is explicitly mentioned. However, it's worth noting that this benchmark does not include ES6+ features (like classes, async/await) since the benchmark definition was written before their introduction in JavaScript.

**Other Alternatives**

For finding the maximum value in an array:

1. **Array.prototype.forEach()**: You can iterate over the array and manually keep track of the maximum value found.
2. **`reduce()` with a loop**: Use `reduce()` method as a starting point, but instead of using the callback function's return value, use a variable to accumulate the results.

Keep in mind that these alternatives might not be as readable or efficient as using the spread operator or the `Array.prototype.reduce()` methods mentioned in this benchmark.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:81.0) Gecko/20100101 Firefox/81.0

Browser/OS: Firefox 81 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
Spread operator	3232565.0 Ops/sec
Array.prototype.reduce()	4160279.2 Ops/sec
Array.prototype.reduce() without arrow function	324410.2 Ops/sec

Related benchmarks:

ES6 spread operator vs. Array.prototype.reduce() (version: 0)

Comparing performance of: Spread operator vs Array.prototype.reduce() vs Array.prototype.reduce() without arrow function

Created: 7 years ago by: Guest

Jump to the latest result

Spread operator

Array.prototype.reduce()

Array.prototype.reduce() without arrow function

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):