Benchmark: findIndex vs for loop with plain number array fixed

Script Preparation code:

var target = 100;
var arr = new Array(15000);
arr.fill([ 500 ]);
arr[8630] = target;

Tests:

findIndex
arr.findIndex((itm) => itm === target);
for loop
for (let i = 0; i < arr.length; i++) { if (arr[i] === target) break; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
findIndex
for loop

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/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Windows

View result in a separate tab

Test name	Executions per second
findIndex	2315.1 Ops/sec
for loop	850.1 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its components.

**Benchmark Overview**

The benchmark is designed to compare the performance of two approaches for finding an object in an array: using the `findIndex` method or a traditional `for` loop with a conditional statement.

**Script Preparation Code**

The script preparation code creates an array `arr` with 15,000 elements and fills it with a single value `[500]`. The value at index `8630` is then set to a specific target value (`100`).

**Html Preparation Code**

There is no HTML preparation code provided.

**Benchmark Definitions**

The benchmark defines two test cases:

1. **findIndex**: This test case uses the `findIndex` method with an arrow function `(itm) => itm === target`. The `findIndex` method returns the index of the first element in the array that satisfies the condition.
2. **for loop**: This test case uses a traditional `for` loop to iterate through the array and find the target value. The loop breaks as soon as it finds the target value.

**Libraries**

There is no explicit library mentioned in the benchmark definitions, but the `findIndex` method is part of the ECMAScript standard (specifically, ECMA-262). This means that this method should be supported by most modern JavaScript engines and browsers.

**Special JS Features/Syntax**

The benchmark uses the arrow function syntax `(itm) => itm === target`, which was introduced in ECMAScript 2015 (ES6). This syntax allows for concise and readable functions without the `function` keyword. The `findIndex` method also supports this syntax, making it a convenient choice for this benchmark.

**Pros and Cons of Each Approach**

Here's a brief summary:

* **findIndex**:
	+ Pros: Concise and readable code, eliminates the need to manually iterate through the array.
	+ Cons: May not be as efficient as a traditional `for` loop if the array is very large, since it still needs to check each element.
* **for loop**:
	+ Pros: Can be more efficient for very large arrays, since it allows manual control over the iteration process.
	+ Cons: Requires more code and can be less readable than using a method like `findIndex`.

**Other Alternatives**

If you need to find an object in an array, there are other approaches you could consider:

* Using `some()` or `every()`: These methods can be used to test whether at least one element in the array satisfies a condition.
* Using `indexOf()` or `lastIndexOf()`: These methods can be used to find the index of a specific value in an array, but they may not be as efficient as using `findIndex`.
* Using a custom loop with manual indexing: This approach allows for fine-grained control over the iteration process, but requires more code and effort.

In summary, the benchmark is designed to compare two common approaches for finding an object in an array. While both methods have their pros and cons, `findIndex` is generally considered a convenient and readable choice for most use cases.

Related benchmarks:

findIndex vs for loop with plain number array fixed (version: 0)

Testing finding an object array via findIndex or by using a for loop

Comparing performance of: findIndex vs for loop

Created: one year ago by: Guest

Jump to the latest result

findIndex

for loop

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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