var test=Array.from({length: 100},()=>Math.random())
test.slice(0,50)
test.filter((e,i)=>i<=50)
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
slice | |
filter |
Test name | Executions per second |
---|---|
slice | 5286579.5 Ops/sec |
filter | 1705283.1 Ops/sec |
Let's break down the provided benchmark definition and test cases.
Benchmark Definition:
The benchmark is comparing two approaches to filter an array of numbers: using slice()
and using filter()
. The goal is to measure which approach performs better in terms of execution time.
Script Preparation Code:
var test = Array.from({ length: 100 }, () => Math.random());
This code creates an array of 100 random numbers using the Array.from()
method and the spread operator (...
). This will be used as the input data for both benchmark tests.
Html Preparation Code: There is no HTML preparation code provided, which means that the browser's JavaScript engine will not have to parse any HTML before running the benchmarks.
Individual Test Cases:
The two test cases are:
slice
test.slice(0, 50)
This line of code uses the slice()
method to extract a subset of 50 elements from the original array starting from index 0.
filter
test.filter((e, i) => i <= 50)
This line of code uses the filter()
method with an arrow function ( anonymous function that takes two arguments, e
and i
) to filter out elements where i
is greater than 50.
Library Usage:
There is no explicit library usage mentioned in the benchmark definition. However, it's worth noting that both slice()
and filter()
are built-in methods of the Array prototype in JavaScript.
Special JS Features or Syntax:
There are a few features used here:
filter()
method uses an arrow function to define the callback function....
): The Array.from()
method uses the spread operator to create an array from an object literal.Pros and Cons of Different Approaches:
slice()
for large arrays due to overhead of iterating over the elementsOther Considerations:
Alternatives:
Other methods for filtering arrays include:
forEach()
with a callback functionreduce()
with an accumulator functionKeep in mind that these alternatives may have trade-offs in terms of performance, readability, or maintainability.