const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9];
const arrayConstructor = new Array(numbers);
const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9];
const arrayLiteral = [numbers];
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
Array constructor | |
Array literal |
Test name | Executions per second |
---|---|
Array constructor | 20133280.0 Ops/sec |
Array literal | 10620871.0 Ops/sec |
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:
...
) to create a new array from an existing array.new Array()
constructor, passing in the elements as separate arguments.Pros and Cons:
Array Literal Syntax:
Pros:
Cons:
Array Constructor:
Pros:
Cons:
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:
Array.from()
(introduced in ES6): const array = Array.from(numbers);
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.