Benchmark: Populate array: array literal vs array constructor

Tests:

Array constructor
const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9]; const arrayConstructor = new Array(...numbers);
Array literal
const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9]; const arrayLiteral = [...numbers];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array constructor
Array literal

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 months ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_5_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/143.0.7499.92 Mobile/15E148 Safari/604.1

Browser/OS: Chrome Mobile iOS 143 on iOS 18.5.0

View result in a separate tab

Test name	Executions per second
Array constructor	22108078.0 Ops/sec
Array literal	419648000.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Goal:**

The primary goal of this benchmark is to compare the performance of two approaches to create an array in JavaScript: using the array literal syntax (`const arrayLiteral = [...numbers];`) versus using the `Array` constructor (`const arrayConstructor = new Array(...numbers);`).

**Options Compared:**

Two options are being compared:

1. **Array Literal Syntax**: This approach uses the spread operator (`...`) to create a new array from an existing array.
2. **Array Constructor**: This approach creates a new array using the `new Array()` constructor, passing in the elements as separate arguments.

**Pros and Cons:**

**Array Literal Syntax:**

Pros:

* More concise and readable
* Less boilerplate code required

Cons:

* May not be supported by older browsers or environments that don't support the spread operator
* Can be slower due to the overhead of creating a new array object and copying elements

**Array Constructor:**

Pros:

* Widely supported across modern browsers and environments
* Allows for more control over array creation, such as setting initial values or options

Cons:

* More verbose and less readable compared to array literal syntax
* Requires explicit type declaration (`const arrayConstructor = new Array(...numbers);`)

**Library Used:**

There is no explicitly mentioned library used in the benchmark. However, it's worth noting that both approaches rely on JavaScript features that are part of the language standard.

**Special JS Feature/Syntax:**

The spread operator (`...`) is a feature introduced in ECMAScript 2015 (ES6). It allows for concise array creation and copying of elements from one array to another. This syntax is also used in modern programming languages, such as TypeScript and Babel.

**Other Alternatives:**

If you were looking for alternative approaches to create an array in JavaScript, some other options could include:

* Using `Array.from()` (introduced in ES6): `const array = Array.from(numbers);`
* Using a loop or recursion to manually create the array
* Utilizing libraries like Lodash or Ramda for array creation and manipulation

Keep in mind that these alternatives might not be as concise or readable as the array literal syntax, but they can provide more control over the array creation process.

In summary, this benchmark aims to measure the performance of two common approaches to create an array in JavaScript: using array literals versus array constructors. The results can help developers and testers understand the trade-offs between these approaches and make informed decisions about which one to use depending on their specific requirements and constraints.

Related benchmarks:

Populate array: array literal vs array constructor (version: 0)

Comparing performance of: Array constructor vs Array literal

Created: 3 years ago by: Guest

Jump to the latest result

Array constructor

Array literal

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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