Benchmark: Object arrays: findIndex vs for loop (Small amount of entries)

Script Preparation code:

var arr = new Array(300);
arr.fill({ id: 0 });
arr = arr.map((el, idx) => el.id = idx);
var foo = Math.floor(Math.random() * 300);

Tests:

findIndex
arr.findIndex((itm) => itm.id === foo);
for loop
for (let i = 0; i < arr.length; i++) { if (arr[i].id === foo) 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/127.0.0.0 Safari/537.36

Browser/OS: Chrome 127 on Windows

View result in a separate tab

Test name	Executions per second
findIndex	59212.0 Ops/sec
for loop	26429.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Overview**

The benchmark being tested is about comparing two approaches to find an element in an array: `Array.prototype.findIndex()` and a traditional `for` loop.

**Options Compared**

There are only two options compared:

1. **`arr.findIndex((itm) => itm.id === foo)`**: This is the first option, which uses the `findIndex()` method to find the index of the element with the matching property value (`foo`).
2. **`for (let i = 0; i < arr.length; i++) { if (arr[i].id === foo) break; }`**: This is the second option, which uses a traditional `for` loop to iterate through the array and find the element with the matching property value.

**Pros and Cons of Each Approach**

1. **`findIndex()` method**:
	* Pros: concise, readable, and efficient for large arrays.
	* Cons: may be slower for small arrays due to overhead of function call.
2. **Traditional `for` loop**:
	* Pros: can be faster for small arrays due to reduced function call overhead, and more control over iteration.
	* Cons: verbose, less readable, and error-prone.

In general, the `findIndex()` method is a good choice when working with large arrays, as it's optimized for performance. However, for small arrays or specific use cases where readability and simplicity matter, the traditional `for` loop might be preferable.

**Library Usage**

The benchmark uses the `Array.prototype.findIndex()` method, which is a built-in JavaScript library function. Its purpose is to find the index of the first element in an array that satisfies a provided condition. In this case, the condition is checking if the `id` property of each element matches the value of `foo`.

**Special JS Features or Syntax**

There are no special JS features or syntax mentioned in the benchmark definition.

**Other Considerations**

When choosing between these two approaches, consider the following:

* Performance: If you're working with large arrays, the `findIndex()` method might be faster due to its optimized implementation.
* Readability and maintainability: For small arrays or simple use cases, the traditional `for` loop might be more readable and easier to understand.

**Alternative Approaches**

Other alternatives for finding an element in an array include:

1. **`some()` method**: Similar to `findIndex()`, but returns `true` as soon as the condition is satisfied.
2. **`forEach()` method**: Iterates through the array, allowing you to perform actions on each element, but doesn't return a value like `findIndex()` or traditional `for` loop does.
3. **`Array.prototype.indexOf()` method**: Returns the index of the first occurrence of the specified element in the array. However, this method is deprecated in favor of `findIndex()` and may not be supported in older browsers.

Keep in mind that these alternatives might have different trade-offs in terms of performance, readability, or functionality, so choose the approach that best fits your specific use case.

Related benchmarks:

Object arrays: findIndex vs for loop (Small amount of entries) (version: 0)

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

Comparing performance of: findIndex vs for loop

Created: 2 years 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):