new Array(500).map((_, index) => index)
Array.from({ length: 500 }, (_, index) => index)
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
new Array() | |
Array.from() |
Test name | Executions per second |
---|---|
new Array() | 1592241.2 Ops/sec |
Array.from() | 75222.9 Ops/sec |
Let's break down the provided benchmark and explain what's being tested, compared options, pros and cons, library usage, and special JavaScript features.
Benchmark Overview
The benchmark is designed to compare the performance of two approaches for creating filled arrays: using new Array()
with a mapping function, and using Array.from()
with an arrow function that returns the index. The goal is to determine which approach is faster and more efficient.
Options Being Compared
There are two options being compared:
new Array() + map()
: This method creates an array of a specified length and then uses the map()
method to transform each element in the array.Array.from()
+ arrow function**: This method creates an array from an iterable (in this case, an object with a
lengthproperty) using the
Array.from()` constructor and provides an arrow function that returns the index.Pros and Cons
Here's a brief summary of the pros and cons of each approach:
new Array() + map()
Array.from()
+ arrow functionArray.from()
Library Usage
Array.from()
is a built-in JavaScript method introduced in ES6 (ECMAScript 2015). It provides a convenient way to create an array from an iterable, which can be useful in many scenarios.
Special JavaScript Features
There are no special JavaScript features being tested or utilized in this benchmark. However, it's worth noting that Array.from()
was not available in older browsers until the introduction of ES6 support. The use of new Array()
+ map() is a more widely supported approach across different browsers and versions.
Other Alternatives
If you're looking for alternative approaches to create filled arrays, here are a few options:
Array.prototype.fill()
: This method was introduced in ECMAScript 2015 (ES6) as a concise way to fill an array with a specified value.new Uint8Array()
or new Int32Array()
: These methods create a typed array, which can be more memory-efficient than regular arrays for specific use cases.In summary, the benchmark is designed to compare two approaches for creating filled arrays in JavaScript: using new Array()
with map(), and using Array.from()
with an arrow function. The results show that Array.from()
+ arrow function is generally faster and more efficient due to optimized engine behavior.