var arr = new Array(10);
arr.fill({ id: 0 });
arr = arr.map((el, idx) => el.id = idx);
var foo = Math.floor(Math.random() * 15000);
var index = arr.findIndex((num) => num === foo);
var index = arr.indexOf(foo);
var index = arr.map((e) => e.id).indexOf(foo);
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
findIndex | |
indexOf | |
map indexOf |
Test name | Executions per second |
---|---|
findIndex | 837345.2 Ops/sec |
indexOf | 4345666.5 Ops/sec |
map indexOf | 1336358.9 Ops/sec |
Let's dive into the explanation of the provided benchmark.
Benchmark Overview
The test case measures the performance difference between three different approaches to find an element in an array:
findIndex()
indexOf()
map()
followed by indexOf()
Library Used: None
There is no library explicitly mentioned in the benchmark definition or the individual test cases. However, we can assume that the standard JavaScript Array methods are being used.
Approaches Compared
foo
). If no element satisfies the condition, it returns -1.findIndex()
, but it performs a loose equality check using the Strict Equality Operator (===
). It also returns -1 if no element matches the specified value.followed by
indexOf(): In this approach, we create a new array with mapped values (in this case, just the index of each element in the original array), and then search for the specified value using indexOf()
.Pros and Cons
indexOf()
since it uses strict equality, which can reduce false positives.foo
) to be present in the array for it to work correctly.foo
(in terms of strict equality).findIndex()
.followed by
indexOf(): Pros:map()
) that can increase overhead.findIndex()
or indexOf()
alone.Other Considerations
Math.floor(Math.random() * 15000)
method to generate a random index (foo
). This is done to ensure that the condition in each test case has an equal chance of being met.Alternatives
If you wanted to explore alternative approaches, here are a few options:
filter()
: Instead of using findIndex()
or indexOf()
, you could use filter()
to find elements that match a certain condition.forEach()
: You could also use forEach()
in conjunction with a callback function to achieve the same result as map()
followed by indexOf()
.binary search
: If the array is sorted or can be easily sorted, you could use binary search to find an element more efficiently than the above approaches.These alternatives might provide different performance characteristics or handling of edge cases compared to the original test case.