Benchmark: Array.prototype.concat vs spread operator for joining arrays

Tests:

ES6 Spread Operator
const foo = [ {a: 'b', c: 'd'}, {a: 'b', c: 'd'}, ]; const bar = [ {a: 'b', c: 'd'}, {a: 'b', c: 'd'}, ]; const baz = [...foo, ...bar];
Array.prototype.concat
const foo = [ {a: 'b', c: 'd'}, {a: 'b', c: 'd'}, ]; const bar = [ {a: 'b', c: 'd'}, {a: 'b', c: 'd'}, ]; const baz = foo.concat(bar);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
ES6 Spread Operator
Array.prototype.concat

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.135 Safari/537.36

Browser/OS: Chrome 84 on Mac OS X 10.15.5

View result in a separate tab

Test name	Executions per second
ES6 Spread Operator	13417912.0 Ops/sec
Array.prototype.concat	4878913.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the explanation of the provided benchmark.

**Benchmark Overview**

The benchmark compares two approaches for joining two complex arrays: the ES6 spread operator (`...`) and `Array.prototype.concat()`. The test case is designed to measure the performance difference between these two methods on a large dataset.

**Options Compared**

Two options are compared:

1. **ES6 Spread Operator**: This approach uses the spread operator (`...`) to concatenate two arrays.
2. **`Array.prototype.concat()`**: This approach uses the `concat()` method of the Array prototype to concatenate two arrays.

**Pros and Cons of Each Approach**

* **ES6 Spread Operator**:
	+ Pros: Efficient, concise, and easy to read.
	+ Cons: May not be supported in older browsers or environments.
	+ Additional note: The spread operator is a relatively new feature introduced in ES6. It's a powerful tool for array manipulation.
* **`Array.prototype.concat()`**:
	+ Pros: Widely supported across modern browsers and environments, including older versions.
	+ Cons: Less concise and less readable than the spread operator.

**Library Used**

There is no explicit library used in this benchmark. The ES6 spread operator is a built-in feature of JavaScript, and `Array.prototype.concat()` is also a built-in method.

**Special JS Feature or Syntax**

The benchmark uses the ES6 spread operator, which introduces a new syntax for array manipulation. This syntax was introduced in ES2015 (also known as ECMAScript 6) and has become a standard feature of modern JavaScript.

**Other Alternatives**

If you're interested in exploring alternative approaches, here are a few options:

1. **Using `Array.prototype.push()`**: You could use the `push()` method to concatenate two arrays by pushing each element from one array into another.
2. **Using `Array.prototype.reduce()`**: You could use the `reduce()` method to concatenate two arrays by reducing an accumulator array and adding elements from both input arrays.

Keep in mind that these alternatives may have different performance characteristics and trade-offs compared to the ES6 spread operator or `Array.prototype.concat()`.

Related benchmarks:

Array.prototype.concat vs spread operator for joining arrays (version: 0)

Comparing ES6 spread against concat for joining two complex arrays.

Comparing performance of: ES6 Spread Operator vs Array.prototype.concat

Created: 4 years ago by: Guest

Jump to the latest result

ES6 Spread Operator

Array.prototype.concat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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