Benchmark: Array.prototype.concat vs spread operator

Tests:

Array.prototype.concat
var params = [ "hello", true, 7 ]; var clone = [ ...params ]; clone.push({something: 'new'});
spread operator
var params = [ "hello", true, 7 ] var clone = params.concat([{something: 'new'}])

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

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

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Let's break down the benchmark and its test cases.

**What is being tested?**

The provided JSON represents two individual test cases that compare the performance of two approaches for creating a new array:

1. `Array.prototype.concat()`: This method creates a new array by concatenating an existing array with another array or array-like object.
2. The **new ES6 spread operator** (`[ ...params ]`): This syntax creates a new array by spreading the elements of an existing array.

**Options compared**

The two test cases are comparing the performance of these two approaches for creating a new array:

* `Array.prototype.concat()`
* The new ES6 spread operator (`[ ...params ]`)

**Pros and Cons of each approach:**

1. **`Array.prototype.concat()`**
	* Pros:
		+ Widely supported across browsers and platforms.
		+ Allows for more control over the resulting array, such as using a `concat()` callback function to modify the new array.
	* Cons:
		+ Can be slower than the spread operator due to the overhead of calling a method and creating a new array.
2. **The new ES6 spread operator (`[ ...params ]`)*
	* Pros:
		+ Fast and efficient, as it only requires creating a new array reference without modifying an existing one.
		+ More concise and expressive code.
	* Cons:
		+ May not be supported in older browsers or platforms.

**Special JS feature/syntax:**

The spread operator (`[ ...params ]`) is a relatively recent addition to JavaScript, introduced in ECMAScript 2015 (ES6). It's part of the new syntax features that allow for more concise and expressive array creation.

**Library usage:**

There are no libraries used in these test cases. The benchmark tests only the native JavaScript implementations of `Array.prototype.concat()` and the spread operator.

**Other considerations:**

When evaluating performance, it's essential to consider factors such as:

* Browser version support
* Platform dependencies (e.g., desktop vs. mobile)
* Execution frequency and concurrency

**Alternatives:**

For creating a new array, other methods can be used, such as:

* `Array.from()`: Creates a new array from an iterable or array-like object.
* `Array.prototype.push()` with an initial value: Creates a new array by pushing elements onto the existing array.

However, these alternatives may have different performance characteristics compared to the spread operator and `concat()`, which is why this benchmark specifically compares those two approaches.

Related benchmarks:

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

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

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

Created: 8 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):