<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>
var size = 10000;
_.range(size);
[Array(size)]
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
lodash range | |
array from |
Test name | Executions per second |
---|---|
lodash range | 23668.9 Ops/sec |
array from | 48331.5 Ops/sec |
Let's break down the provided benchmark and explain what is being tested.
Benchmark Description
The benchmark measures the performance of two different ways to create an array in JavaScript: using _.range()
from Lodash, and using the spread operator ([...]
) with Array(size)
.
Options Compared
_range()
: This function generates a new array of numbers starting from 0 and incrementing by 1 until it reaches the specified size.Array.from([...])
: This creates a new array by duplicating an existing iterable (in this case, an array with a single element). The ...
spread operator is used to create the new array.Pros and Cons of Each Approach
_range()
:Array.from([...])
:_range()
directly.Other Considerations
Both approaches have different use cases. If you need to generate a sequence of numbers for processing or iteration, _.range()
might be a better choice. However, if you're working with existing arrays and want to create a new one by duplicating it, the spread operator is often sufficient.
Special JavaScript Feature/Syntax
The benchmark uses ES6 syntax (e.g., var size = 10000;
, [...Array(size)]
) and also imports Lodash library via a CDN (<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>
). No special features or syntax are used here.
Other Alternatives
For creating arrays, other approaches exist:
Array()
: new Array(size)
Array.from(iterable)
: This creates a new array from an existing iterable (e.g., another array).concat()
: Array.concat(new Array(size))
However, these alternatives might not be as concise or readable as using the spread operator or _range()
.
Benchmark Result
The benchmark result shows that Chrome 104 on a desktop with Mac OS X 10.15.7 is executing Array.from([...])
approximately 2.6x faster than _.range(size)
, which might not be surprising given their different use cases and performance characteristics.