let a = []; for(let i=0; i <= 1000; i=i+1) { a = [a, i ]; };
const a = []; for(let i=0; i <= 1000; i = i + 1) { a.push(i); };
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
array construct | |
array push |
Test name | Executions per second |
---|---|
array construct | 898.2 Ops/sec |
array push | 181452.5 Ops/sec |
Let's break down the provided JSON and explain what is tested in each benchmark.
Benchmark Definition
The benchmark definition defines two tests:
Array Construct
: This test measures the performance of creating an array using the spread operator ([...a, i]
) compared to the traditional way of appending elements to an existing array.Array Push
: This test measures the performance of using the push()
method to append elements to an existing array.Options Compared
In both tests, two approaches are being compared:
[...a, i]
): This approach creates a new array by spreading the contents of an existing array (a
) and appending a new element (i
). The spread operator is a modern JavaScript feature introduced in ECMAScript 2015.a = [...a, i];
): This approach modifies the original array a
by using the assignment operator to create a new array with the appended element.Pros and Cons
Here's a brief analysis of each approach:
[...a, i]
):a = [...a, i];
):Other considerations:
Library
There are no libraries mentioned in the provided benchmark definition. All tests rely on built-in JavaScript features.
Special JS Feature or Syntax
The spread operator ([...a, i]
) is a special JavaScript feature introduced in ECMAScript 2015 (ES6). It allows for concise and expressive array creation and manipulation.
Other Alternatives
If you're interested in exploring alternative approaches to creating arrays, here are some other options:
Array.prototype.push()
: Instead of modifying an existing array, you can create a new array using the push()
method. This approach is more memory-efficient but may be less concise and readable.Array.concat()
: Another way to concatenate arrays is by using the concat()
method. However, this approach has similar performance characteristics to traditional append.Keep in mind that these alternative approaches might not provide significant performance benefits for most use cases, especially with modern JavaScript engines that optimize array operations efficiently.