<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js'></script>
var size = 1000;
_.range(size);
[Array(size).keys()]
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
Lodash | |
Spread operator |
Test name | Executions per second |
---|---|
Lodash | 300140.8 Ops/sec |
Spread operator | 19687.3 Ops/sec |
Let's break down what's happening in this benchmark.
What is being tested?
The website, MeasureThat.net, runs JavaScript microbenchmarks to compare the performance of different approaches for creating arrays of fixed size. The two test cases measure:
_range
function to create an array of size
elements....
) with an array comprehension [...Array(size).keys()]
.Options being compared
The benchmark compares the performance of these two approaches.
Pros and Cons of each approach:
_range
function:_range
function is likely optimized for performance....
) with array comprehension:Library usage
The Lodash library is used in the first test case to provide its _range
function. Lodash (short for "Lisp-like") is a popular JavaScript utility library that provides various functions for tasks such as:
+ Array manipulation and iteration
+ String manipulation and formatting
+ Object creation and manipulation
+ Miscellaneous utilities
Special JS features or syntax
The spread operator (...
) is used in the second test case to create an array. This is a modern JavaScript feature introduced in ECMAScript 2015 (ES6).
Other alternatives for creating arrays of fixed size include:
Array.from()
: Introduced in ES6, this method creates a new array from an iterable source.new Array(size)
: Creates a new array object with the specified number of elements.These alternatives may have different performance characteristics depending on the specific use case and JavaScript engine being used.
In summary, the benchmark measures the performance of two approaches for creating arrays of fixed size: using Lodash's _range
function versus the spread operator with an array comprehension. The pros and cons of each approach are considered, along with a brief explanation of the Lodash library and the modern spread operator syntax.