var array1 = [];
array1[1000] = 2;
var array2 = [];
for(i=0; i<=1000; i++){
array2[i] = 1;
}
array1.map(item => item)
array2.map(item => item)
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
empty elements | |
no empties |
Test name | Executions per second |
---|---|
empty elements | 429547.3 Ops/sec |
no empties | 173008.2 Ops/sec |
Let's break down the benchmark and explain what's being tested, compared, and their pros and cons.
Benchmark Overview
The benchmark is designed to measure the performance of the map()
function in JavaScript, which applies a given function to each element of an array and returns a new array with the results. The test cases are:
empty elements
: An empty array is created (array1
) and then modified by assigning a value to its 1000th index. Another empty array (array2
) is created, but it's not used in the benchmark.no empties
: Similar to the first test case, an empty array is created, but this time it's not modified.Comparison of Options
The benchmark compares two approaches:
Pros and Cons of Each Approach
map()
, where the array is modified in some way.map()
function, which may not accurately represent its performance when used with actual data.map()
, and the benchmark results might not be representative of real-world use cases.Libraries and Special JS Features
There are no libraries mentioned in the provided benchmark code. However, it's worth noting that some JavaScript engines may have specific optimizations or features related to array operations or memory management that could affect performance.
Special JS Feature: item => item
Syntax
This syntax is a shorthand for a function literal with a single expression. In this context, it simply returns the input value without modification. This syntax is widely supported in modern JavaScript engines and is often used as a placeholder or example code.
Other Alternatives
Some alternative approaches to measuring map()
performance could include:
forEach()
or reduce()