Benchmark: Array concat vs spread operator vs push vs spread spread

Tests:

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator
Push
spread spread

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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I'll break down the benchmark for you.

**What is being tested?**

The test cases compare different ways to concatenate arrays in JavaScript:

1. `Array.prototype.concat()`
2. The new ES6 spread operator (`...`)
3. The `push()` method with a rest parameter (`...`)

These alternatives offer different performance and readability trade-offs.

**Options compared:**

* **Array.prototype.concat()**: This is the traditional way to concatenate arrays in JavaScript. It creates a new array by copying elements from both source arrays.
	+ Pros:
		- Well-supported across browsers
		- Easy to read and understand
	+ Cons:
		- Creates a new array, which can be memory-intensive for large datasets
		- Can be slower than other methods due to the overhead of creating a new array
* **The spread operator (`...`)**: This is a newer way to concatenate arrays introduced in ES6. It uses the `...` syntax to spread elements from one or more source arrays into another array.
	+ Pros:
		- More concise and expressive than traditional methods
		- Can be faster than creating a new array with concat()
		- Reduces memory allocation overhead
* **Push() method with rest parameter (`...`)**: This is similar to the spread operator, but uses the `push()` method to add elements to an existing array.
	+ Pros:
		- Same benefits as the spread operator (concise, faster, and reduced memory allocation)
		- May be more readable for those familiar with the push() method

**Library and special JS features:**

None of these alternatives rely on any external libraries or special JavaScript features. They are all built-in to JavaScript.

**Benchmark result analysis:**

The benchmark results show that:

* The spread operator (`...`) is the fastest, followed closely by `push()` with a rest parameter.
* `Array.prototype.concat()` is slower than the other two alternatives.

This suggests that these modern array concatenation methods are optimized for performance and can take advantage of certain CPU architectures.

**Alternatives:**

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

1. **Using Array.from()**: This method creates a new array from an iterable (like an array) using the spread operator (`...`). While it may seem similar to other methods, it has its own performance characteristics and is worth testing.
2. **Using slice()**: This method returns a shallow copy of a portion of an array. It can be used as an alternative to concat(), but keep in mind that it creates a new array.
3. **Using for loops**: You could use traditional for loops to concatenate arrays, but this would likely be the slowest option due to the overhead of manual iteration.

In conclusion, the spread operator and `push()` method with rest parameters are good choices when concatenating arrays in JavaScript, as they offer a balance between readability, performance, and memory efficiency. However, if you're working on a project where performance is critical or have specific requirements, exploring alternative approaches may be worth considering.

Related benchmarks:

Array concat vs spread operator vs push vs spread spread (version: 0)

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

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

Created: 5 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Push

spread spread

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):