Benchmark: Array concat vs spread operator vs push with objects

Tests:

Array.prototype.concat
var params = [ {a: 3}, {a: 4}, {a: 5} ]; var other = [ {a: 1}, {a: 2} ].concat(params);
spread operator
var params = [ {a: 3}, {a: 4}, {a: 5} ]; var other = [ {a: 1}, {a: 2}, ...params ]
Push
var params = [ {a: 3}, {a: 4}, {a: 5} ]; var other = [ {a: 1}, {a: 2} ].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

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:93.0) Gecko/20100101 Firefox/93.0

Browser/OS: Firefox 93 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	7502277.5 Ops/sec
spread operator	8754404.0 Ops/sec
Push	6623293.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what's being tested, compared, and some of the pros and cons.

**Benchmark Definition**

The benchmark is comparing three different approaches to concatenate or merge arrays in JavaScript:

1. `Array.prototype.concat()`
2. The new ES6 spread operator (`...`)
3. `Array.prototype.push()` with the spread operator (`...`)

**Purpose of each approach:**

* `Array.prototype.concat()`: This method creates a new array by concatenating two or more arrays.
* The spread operator (`...`): This operator allows you to expand an iterable (like an array) into individual elements, which can be used as arguments in function calls or as values in object literals. When used with the `Array.prototype.push()` method, it allows you to push multiple elements onto an array at once.
* `Array.prototype.push()` with the spread operator (`...`): This approach uses the spread operator to pass multiple elements to the `push()` method, allowing it to concatenate or merge arrays.

**Pros and Cons:**

* `Array.prototype.concat()`: Pros:
	+ Easy to understand and use
	+ Works well for concatenating small to medium-sized arrays
	+ Has been part of JavaScript for a long time
Cons:
	+ Creates a new array, which can be memory-intensive
	+ Can be slower than other approaches for large arrays
* The spread operator (`...`): Pros:
	+ More concise and expressive than `Array.prototype.concat()`
	+ Works well for merging small to medium-sized arrays
	+ Has been part of JavaScript for a long time
Cons:
	+ Can be slower than `Array.prototype.concat()` for very large arrays
	+ May not work as expected in older browsers or environments that don't support the spread operator
* `Array.prototype.push()` with the spread operator (`...`): Pros:
	+ More concise and expressive than calling `push()` multiple times
	+ Works well for merging small to medium-sized arrays
Cons:
	+ Can be slower than using `Array.prototype.concat()`
	+ May not work as expected in older browsers or environments that don't support the spread operator

**Library Usage:**

None of the approaches mentioned above rely on external libraries. They are all built-in JavaScript methods.

**Special JS Features or Syntax:**

The use of the spread operator (`...`) is a new feature introduced in ES6, which allows for more concise and expressive array manipulation. It's also used to pass multiple elements to functions that expect an iterable as an argument.

**Other Alternatives:**

Some other alternatives to concatenate arrays include:

* Using `Array.prototype.splice()` to remove and replace elements
* Creating a new array using the `Array.from()` method
* Using a library like Lodash, which provides various utility methods for working with arrays

Note that these alternatives may not be as concise or expressive as the spread operator approach, but they can provide more control over the merging process.

Related benchmarks:

Array concat vs spread operator vs push with objects (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: 3 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Push

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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