Benchmark: Array fill map, vs for i loop

Script Preparation code:

var iterations = 10000;

Tests:

for
for (i = 0; i < iterations; i++) { console.log(i); }
fill and map
Array(iterations).fill('').map((value, index) => console.log(index));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
fill and map

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 3 days ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition and test cases to explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The website MeasureThat.net allows users to create and run JavaScript microbenchmarks. The provided benchmark definition represents a comparison between two approaches:

1. **For loop**: A traditional for loop that iterates over an array using a counter variable `i`.
2. **Array fill and map**: Using the `fill` method to initialize an array with a specified length, followed by applying the `map` method to iterate over the array.

**Options Compared**

In this benchmark, we're comparing two approaches:

* For loop (`"for"` )
* Array fill and map (`"fill and map"` )

These two approaches differ in how they handle iteration and element manipulation. The for loop is a traditional, low-level approach that requires manual management of the counter variable `i`. In contrast, array fill and map provide a higher-level abstraction by using built-in methods to initialize and iterate over an array.

**Pros and Cons**

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

* For loop:
	+ Pros: Lightweight, no additional memory allocation required.
	+ Cons: Error-prone, requires manual management of the counter variable `i`.
* Array fill and map:
	+ Pros: Concise, eliminates the need for manual counter management. Provides a higher-level abstraction.
	+ Cons: May incur overhead due to method calls and memory allocation.

**Library/Feature Used**

In this benchmark, we're using:

* `Array` (built-in JavaScript array object)
* `fill` and `map` methods (part of the ECMAScript standard)

These methods provide a convenient way to initialize and iterate over arrays without requiring manual management of counters or indices. The `fill` method initializes an array with a specified length, while the `map` method applies a transformation function to each element in the array.

**Special JS Feature/Syntax**

No special JavaScript features or syntax are used in this benchmark. It's designed to be platform-agnostic and testable using standard JavaScript implementations.

**Alternative Approaches**

Other alternatives for iterating over arrays include:

* `forEach`: A method that calls a callback function on each element of an array, without the need for manual counter management.
* Loops with increment/decrement operators (`++` and `--`) to iterate over arrays.
* Using `Array.prototype.reduce()` or `Array.prototype.findIndex()` methods.

These alternatives may offer different performance characteristics or trade-offs in terms of readability and maintainability. However, they are not explicitly compared in this benchmark definition.

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/119.0.0.0 Safari/537.36

Browser/OS: Chrome 119 on Windows

View result in a separate tab

Test name	Executions per second
for	15.5 Ops/sec
fill and map	17.2 Ops/sec

Related benchmarks:

Array fill map, vs for i loop (version: 0)

People tend to use array fil and then foreach, we know foreach is faster than a for loop, but is it also faster if you use array fill first?

Comparing performance of: for vs fill and map

Created: one year ago by: Guest

Jump to the latest result

for

fill and map

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Sumamry (model llama3.2:3b, generated 3 days ago):