Benchmark: Array.prototype.concat vs spread operator vs push vs spread vs apply

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

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator
Push
spread operator 2
Apply

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's break down what is being tested in this benchmark.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark that compares the performance of four different approaches for concatenating or adding elements to an array:

1. `Array.prototype.concat()`
2. The spread operator (`...`)
3. The `push()` method
4. The `apply()` method

**Options compared**

Each test case evaluates one of these four options in isolation.

**Pros and Cons of each approach:**

* **`Array.prototype.concat()`**: This is the traditional way of concatenating arrays in JavaScript. It's a built-in method that creates a new array by copying elements from two source arrays. While it works, it can be slower than other methods because it involves creating a new object.
	+ Pros: Well-established and widely supported; no additional libraries needed.
	+ Cons: Can be slower due to object creation; may not be suitable for very large arrays.
* **The spread operator (`...`)**: Introduced in ES6, this operator allows you to create a new array by spreading elements from an existing array or value. It's a concise way of creating new arrays without using the `concat()` method.
	+ Pros: Concise and expressive; can be faster than `concat()`.
	+ Cons: May not work as expected in older browsers that don't support ES6 features; requires careful handling of edge cases (e.g., null or undefined values).
* **The `push()` method**: This is another way to add elements to an array. Instead of creating a new array, you can simply append elements to the existing one.
	+ Pros: Can be faster than `concat()` because it avoids object creation; suitable for adding small numbers of elements.
	+ Cons: May not work as expected if you need to concatenate multiple arrays; requires careful handling of edge cases (e.g., array indexing).
* **The `apply()` method**: This is a bit more complex, as it takes an optional second argument (the context object) and applies the provided function to that context. In this benchmark, it's used to add elements to an array by calling the `push()` method on each element individually.
	+ Pros: Can be faster than `concat()` because it avoids object creation; suitable for adding small numbers of elements.
	+ Cons: May not work as expected if you need to concatenate multiple arrays; requires careful handling of edge cases (e.g., array indexing).

**Other considerations**

When using these methods, keep in mind:

* When working with very large arrays, the performance differences between these methods may become negligible due to memory constraints.
* Be cautious when dealing with edge cases like null or undefined values, which can affect the behavior of these methods.

Now, let's move on to individual test cases and their corresponding libraries:

**Individual Test Cases**

Each test case uses a specific array initialization method, such as `var params = [ \"hello\", true, 7 ];`. This is not explicitly mentioned in the provided JSON, but I assume it's using a common array initialization syntax.

In terms of special JS features or syntax, none are explicitly mentioned. The focus is on the performance comparison between these four approaches.

**Alternative approaches**

If you need to concatenate arrays, consider using a library like `lodash`, which provides efficient and expressive ways to work with arrays, such as `_.concat()` or `_.merge()`. However, be aware that this may add additional dependencies to your project.

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.67 Safari/537.36

Browser/OS: Chrome 70 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	6037235.0 Ops/sec
spread operator	23905730.0 Ops/sec
Push	23568198.0 Ops/sec
spread operator 2	5412549.0 Ops/sec
Apply	4337194.5 Ops/sec

Related benchmarks:

Array.prototype.concat vs spread operator vs push vs spread vs apply (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 operator 2 vs Apply

Created: 6 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Push

spread operator 2

Apply

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):