Benchmark: Array ForEach vs Find vs for loop (2)

Script Preparation code:

var arr = [];
for (var i = 0; i < 10000; i++) {
  arr[i] = i;
}
var needToFindThis = Math.floor((Math.random() * 10000) + 1);

Tests:

ForEach
var indexFound = -1; arr.forEach((item, index) => { if (item === needToFindThis) { indexFound = index; } });
Find
var indexFound = arr.find((item, index) => { if (item === needToFindThis) { return index; } });
For
var indexFound = -1; for (var i = 0; i < arr.length; i++) { if (arr[i] === needToFindThis) { indexFound = i; break; } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
ForEach
Find
For

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser/OS: Chrome 121 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
ForEach	2889.5 Ops/sec
Find	23684.5 Ops/sec
For	8698.4 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 provided benchmark and explain what's being tested, compared, and their pros and cons.

**Overview**

The benchmark is testing three different approaches to find an element in an array:

1. `Array.prototype.forEach()`
2. `Array.prototype.find()`
3. A traditional `for` loop

**Library Used**

None specific libraries are used in this benchmark. However, the `find()` method relies on a library called "Lodash" which is not included in this JSON.

**JavaScript Features/Syntax**

The benchmark uses JavaScript's built-in `forEach()` and `find()` methods, as well as a traditional `for` loop with the `break` statement.

Here's a brief explanation of each approach:

1. **Array.prototype.forEach()**: This method iterates over an array using a callback function, allowing you to perform actions on each element. In this case, it's used to find an element in the array by comparing it with the target value.
2. **Array.prototype.find()**: This method returns the first element in the array that satisfies a provided testing function (also known as the "predicate"). If no elements satisfy the testing function, `find()` returns `undefined`. In this case, it's used to find an element by comparing it with the target value and returning its index.
3. **Traditional For Loop**: This is a basic `for` loop that iterates over an array using an index variable. When the condition is met, the `break` statement exits the loop.

**Pros and Cons**

1. **Array.prototype.forEach()**:
	* Pros: Easy to use, concise syntax.
	* Cons: Can be slower than traditional loops, as it creates a new scope for each iteration.
2. **Array.prototype.find()**:
	* Pros: Convenient when you only need to find one element, relatively fast.
	* Cons: Returns `undefined` if no elements match, and can be slower for large arrays.
3. **Traditional For Loop**:
	* Pros: Can be faster than `forEach()` or `find()` methods, as it avoids the overhead of creating a new scope.
	* Cons: More verbose syntax, requires manual index management.

**Alternative Approaches**

Other approaches to find an element in an array include:

1. Using `Array.prototype.includes()`: This method is more concise and can be faster than traditional loops.
2. Using `Map` or `Set` data structures: These provide efficient lookups for elements in the collection.

In general, the choice of approach depends on the specific requirements of your application, such as performance, readability, and maintainability.

Related benchmarks:

Array ForEach vs Find vs for loop (2) (version: 0)

Comparing performance of: ForEach vs Find vs For

Created: 4 years ago by: Guest

Jump to the latest result

ForEach

Find

For

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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