const arr = [{id:'A'}, {id:'B'}, {id:'C'}, {id:'D'}, {id:'E'}, {id:'F'}];
const item = arr.find(i=>i.id === 'C')
const obj = {
'A':{},
'B':{},
'C':{},
'D':{},
'E':{},
'F':{}
}
const item = obj['C']
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
array find | |
object index |
Test name | Executions per second |
---|---|
array find | 25212678.0 Ops/sec |
object index | 694619648.0 Ops/sec |
Let's break down the provided benchmark and explain what's being tested, compared, and their pros and cons.
Benchmark Purpose:
The main goal of this benchmark is to compare the performance of two different approaches to access and find an element in an array or object. Specifically, it tests array.find()
vs object['key']
.
Options Compared:
arr.find()
): This method returns the first element in the array that satisfies the provided testing function. If no elements satisfy the testing function, undefined is returned.obj['key']
): This method directly accesses an object property using bracket notation.Pros and Cons of Each Approach:
arr[0]
instead of arr['0']
).obj['C']
instead of obj['c']
) if not careful.Library Used: None. These methods are built-in JavaScript features, not requiring any external libraries.
Special JS Feature/Syntax:
The benchmark uses the " Rest Spread Syntax" (...
) in the script preparation code, which is not relevant to this specific comparison (array find vs object index). However, it's worth noting that this syntax can be used to create new arrays or objects with spreadable properties.
Alternative Approaches:
Array.prototype.findIndex()
: Similar to arr.find()
, but returns the index of the first element that satisfies the testing function instead of the element itself.Object.keys()
and indexOf()
: Another approach is to use Object.keys()
to get an array of keys for the object, then use indexOf()
to find the index of the desired key.In general, when working with arrays and objects in JavaScript, it's essential to consider performance, readability, and maintainability when choosing the best approach.