Benchmark: find vs findIndex (Array prototype methods) (compare for inclusion)

Script Preparation code:

var arr = [];
var i = 0;

while (i <= 1E5) arr[i] = i++;

Tests:

Array.prototype.find
const includesItem = arr.find(item => item == 1E5) !== null;
Array.prototype.findIndex
const includesItem = arr.findIndex(item => item == 1E5) !== -1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.find
Array.prototype.findIndex

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36

Browser/OS: Chrome 112 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.find	939.9 Ops/sec
Array.prototype.findIndex	900.3 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON benchmark definition and individual test cases to understand what is being tested, compared, and the pros and cons of different approaches.

**Benchmark Definition:**

The benchmark measures which is faster:

* `find(predicate) !== null`
* `findIndex(predicate) !== -1`

These two methods are used to search for a specific value in an array. However, there's a subtle difference between them:

* `find()` returns the first element that satisfies the provided condition, or `undefined` if no element matches. It also includes the value in the result (e.g., `null` or `undefined`) when it finds a match.
* `findIndex()` returns the index of the first element that satisfies the provided condition, or `-1` if no element matches. Unlike `find()`, it does not include the value in the result.

**Library and Purpose:**

The benchmark uses the `Array.prototype.find()` and `Array.prototype.findIndex()` methods, which are built-in JavaScript functions. These methods are part of the ECMAScript standard and do not require any additional libraries to be included.

These methods were introduced in ECMAScript 2015 (ES6) as a way to simplify array manipulation and make it more expressive. They provide a concise way to search for elements in arrays, making your code more readable and maintainable.

**Special JS Features:**

* `const` keyword: This keyword is used to declare variables that cannot be reassigned. It's a modern JavaScript feature introduced in ECMAScript 2015 (ES6). The `const` keyword ensures that the value of the variable remains constant throughout the execution of the program.
* Template literals (`item == 1E5`): This syntax allows you to create strings by inserting expressions inside backticks (`). The `==` operator is used for loose equality comparison, which means it performs a value-of comparison rather than an identity comparison.

**Options Compared:**

The benchmark compares two options:

1. Using `find()` with the `===` operator (strict equality) instead of `==` (loose equality).
2. Using `findIndex()` with the `===` operator instead of `==`.

These options are compared to understand which method is faster and more efficient in terms of performance.

**Pros and Cons:**

Here's a brief summary of the pros and cons of each option:

* **Using `find()` with `===`:**
	+ Pros:
		- Can be more readable, especially when working with complex conditions.
		- Can provide better feedback on incorrect values (e.g., null or undefined).
	+ Cons:
		- May include the value in the result if it matches.
		- Might perform slower due to the overhead of comparing with `===`.
* **Using `findIndex()` with `===`:**
	+ Pros:
		- Does not include the value in the result, which might be beneficial for certain use cases (e.g., avoiding null or undefined values).
		- Often faster than using `find()` because it returns an index instead of a value.
	+ Cons:
		- Requires more explicit indexing and handling of -1 edge case.
		- Might have less readable code due to the use of indexing.

**Alternatives:**

If you need to search for elements in an array, here are some alternative approaches:

* **Using `some()` and `every()`:**
	+ Pros:
		- Can be more expressive when working with complex conditions.
		- Often faster than using `find()` or `findIndex()`.
	+ Cons:
		- May have less readable code due to the use of multiple functions.
* **Using a custom loop:**
	+ Pros:
		- Can provide total control over the search process.
		- Might be more efficient for very large arrays.
	+ Cons:
		- Requires manual indexing and iteration, which can lead to errors or performance issues.

In summary, the benchmark compares two methods (`find()` and `findIndex()`) with different approaches (using `===` vs. `==`) to determine which one is faster and more efficient.

Related benchmarks:

find vs findIndex (Array prototype methods) (compare for inclusion) (version: 0)

Measuring which is faster: `find(predicate) !== null` or `findIndex(predicate) !== -1`

Comparing performance of: Array.prototype.find vs Array.prototype.findIndex

Created: one year ago by: Guest

Jump to the latest result

Array.prototype.find

Array.prototype.findIndex

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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