Benchmark: indexOf vs findIndex with a simple case

Script Preparation code:

const size = 15000;
var arr = new Array(15000).fill(0).map((_, i) => i);
var foo = Math.floor(Math.random() * size);

Tests:

indexOf
var index = arr.indexOf(foo);
findIndex
var index = arr.findIndex(a => a === foo);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
indexOf
findIndex

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

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Let's break down the provided JSON and explain what is tested in the benchmark.

**Benchmark Definition**

The benchmark measures the performance difference between two JavaScript methods: `indexOf` and `findIndex`. The benchmark definition is simply an empty string, which means that the script preparation code is responsible for setting up the environment.

**Script Preparation Code**

The script preparation code generates a large array of 15,000 elements with random values. This creates a scenario where both `indexOf` and `findIndex` methods will be used to search for a specific value (`foo`) within the array.

**Html Preparation Code**

There is no HTML preparation code provided, which means that this benchmark does not involve rendering any complex web pages or interacting with DOM elements.

**Test Cases**

The benchmark consists of two test cases:

1. `indexOf`: This test case measures the performance of the `indexOf` method when searching for a specific value within the array.
2. `findIndex`: This test case measures the performance of the `findIndex` method when searching for a specific value within the array.

**Library and Syntax**

Neither `indexOf` nor `findIndex` uses any external libraries or special JavaScript features. These are built-in methods in JavaScript that can be used directly without requiring any additional setup or dependencies.

**Options Compared**

The benchmark is comparing two different approaches:

1. `indexOf`: This method searches for the first occurrence of a specified value within the array and returns its index. If the value is not found, it returns -1.
2. `findIndex`: This method finds the index of the first occurrence of a specified value within the array that satisfies a predicate function. The predicate function takes a single argument (the element being tested) and returns a boolean value.

**Pros and Cons**

Here are some pros and cons of each approach:

* `indexOf`:
	+ Pros: Generally faster, more straightforward to use.
	+ Cons: Returns -1 if the value is not found, which can lead to unexpected behavior in some cases.
* `findIndex`:
	+ Pros: Allows for a custom predicate function that can make the search more complex and flexible.
	+ Cons: May be slower than `indexOf` due to the additional overhead of evaluating the predicate function.

**Other Considerations**

In addition to performance, there are other considerations when choosing between `indexOf` and `findIndex`. For example:

* If you need to find the index of a specific value in an array, but also want to perform some additional operation on that value (e.g., filtering or mapping), `findIndex` might be a better choice.
* If you're working with arrays that contain complex data structures (e.g., objects or arrays within arrays), `indexOf` might be a better choice because it's generally faster and more straightforward.

**Alternatives**

If you want to explore alternative approaches, here are some options:

* Using `Array.prototype.some()` or `Array.prototype.every()`: These methods can provide similar functionality to `findIndex`, but with different syntax and behavior.
* Using a third-party library (e.g., Lodash): These libraries often provide optimized implementations of common array operations, including `indexOf` and `findIndex`.
* Implementing your own custom search algorithm: Depending on the specific requirements of your project, you might be able to optimize or replace these built-in methods with a custom implementation.

Related benchmarks:

indexOf vs findIndex with a simple case (version: 0)

Comparing performance of: indexOf vs findIndex

Created: 5 years ago by: Guest

Jump to the latest result

indexOf

findIndex

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):