Benchmark: Array.prototype.concat vs spread operator magic

Tests:

Array.prototype.concat
var base = [1 , 2] var params = [ "hello", true, 7 ]; var other = base.concat(params);
spread operator
var base = [1 , 2] var params = [ "hello", true, 7 ] var other = [ ...base, ...params ]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

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

**What is tested?**

The test compares two approaches for concatenating arrays in JavaScript:

1. The traditional `Array.prototype.concat()` method.
2. The new ES6 spread operator (`...`) for array concatenation.

**Options compared:**

* Traditional `concat()` method
* Spread operator (`...`)

**Pros and Cons of each approach:**

* **Traditional `concat()` method:**
	+ Pros:
		- Wide browser support (has been around since JavaScript 1.0)
		- Well-documented and widely understood
	+ Cons:
		- Can be slower than the spread operator due to the overhead of calling a method on an array
		- Requires a separate array creation step, which can lead to increased memory usage
* **Spread operator (`...`):**
	+ Pros:
		- Faster execution time compared to `concat()`
		- More concise and expressive syntax
	+ Cons:
		- Requires modern JavaScript engines (ES6+) for proper support
		- Can be less intuitive for developers who are not familiar with the spread operator

**Library and its purpose:**

None mentioned in the provided benchmark. However, it's worth noting that the `concat()` method is a part of the built-in `Array` prototype in JavaScript.

**Special JS feature or syntax:**

The spread operator (`...`) is a new feature introduced in ES6 (2015). It allows for concise array creation and expansion.

**Other alternatives:**

* **Array.prototype.push()**: While not exactly equivalent to concatenation, using `push()` can be an alternative approach. However, it requires creating a new array and then pushing each element individually.
* **Array.prototype.slice()**: Another alternative is to use `slice()` to create a shallow copy of the original array and then append the new elements.

**Benchmark preparation code and test cases:**

The benchmark provides two test cases:

1. Using `concat()` method:
```javascript
var base = [1, 2];
var params = ["hello", true, 7];
var other = base.concat(params);
```
2. Using spread operator (`...`):
```javascript
var base = [1, 2];
var params = ["hello", true, 7];
var other = [...base, ...params];
```

**Benchmark result:**

The latest benchmark result shows the execution performance for each test case:

* `Array.prototype.concat()`: approximately 16.66 million executions per second
* `spread operator (`...`): approximately 9.0125 million executions per second

Keep in mind that these results may vary depending on the specific browser, device, and system configuration used for the benchmark.

Related benchmarks:

Array.prototype.concat vs spread operator magic (version: 0)

Compare the new ES6 spread operator with the traditional concat() method

Comparing performance of: Array.prototype.concat vs spread operator

Created: 3 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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