Benchmark: Array concat vs spread operator vs push (self appending)

Script Preparation code:

var results = {concat: [], spread: [], push: []}
var params = Array.from({length: 10}, () => Math.floor(Math.random() * 10))

Tests:

Array.prototype.concat
results.concat = results.concat.concat(params)
spread operator
results.spread = [...results.spread, ...params]
Push
results.push.push(...params)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

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 explain what's being tested.

**Benchmark Overview**

The benchmark compares the performance of three approaches to append an array to another array:

1. **`Array.prototype.concat()`**: The traditional method of concatenating arrays using the `concat()` method.
2. **Spread Operator (`...`)**: The new ES6 spread operator, introduced in ECMAScript 2015, which allows for more concise and expressive array creation.
3. **`push()` method with spread syntax (`...`)**: A variation of the `push()` method that uses the spread operator to append elements.

**Options Compared**

The benchmark tests each approach on a large dataset (10 random integers) and measures their performance in terms of executions per second.

**Pros and Cons of Each Approach:**

1. **`Array.prototype.concat()`**:
	* Pros:
		+ Wide support across older browsers
		+ Easy to implement
	* Cons:
		+ May lead to slower performance due to the overhead of creating a new array object
		+ Less expressive than modern alternatives
2. **Spread Operator (`...`)**:
	* Pros:
		+ More concise and expressive than traditional concatenation
		+ Can be faster for large datasets due to reduced overhead
	* Cons:
		+ May not work as expected in older browsers or environments with limited support for ES6 features
3. **`push()` method with spread syntax (`...`)**:
	* Pros:
		+ Combines the best of both worlds: concise and expressive, while still using a familiar `push()` method
	* Cons:
		+ May have slightly higher overhead than the spread operator alone due to the additional method call

**Library and Purpose**

None of the libraries are explicitly mentioned in the benchmark configuration. However, it's worth noting that the spread operator relies on the `Array.prototype` prototype chain, which is a fundamental aspect of JavaScript.

**Special JS Features or Syntax**

The benchmark uses ES6 features such as:

1. **Spread Operator (`...`)**: A new syntax introduced in ECMAScript 2015 for creating arrays and objects.
2. **Template Literals (`\r\n`)**: Used to create multiline strings.

These features are widely supported across modern browsers, but may not work as expected in older environments.

**Alternatives**

Other alternatives for appending arrays could include:

1. **Using `Array.prototype.splice()`**: Instead of concatenating or pushing new elements, you can use `splice()` to replace an existing element with a new array.
2. **Utilizing libraries like Lodash**: Lodash provides various utility functions for working with arrays, including `concat` and `push`.
3. **Implementing custom array append functionality**: Depending on the specific requirements, you might consider implementing your own custom solution for appending arrays.

Keep in mind that these alternatives may have their own trade-offs in terms of performance, readability, and compatibility.

Related benchmarks:

Array concat vs spread operator vs push (self appending) (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

Created: 6 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Push

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):