Benchmark: for vs map to fill array

Script Preparation code:

qty = 50;
value = "lol";

Tests:

for
const arr = []; for (let i = 0; i < qty; i++) arr.push(value);
map
const arr = Array(3); arr.map(() => value);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
map

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's dive into explaining the benchmark.

**What is tested?**

The provided JSON represents two individual test cases, both designed to measure the performance difference between using a `for` loop and an array `map()` method in JavaScript. The test case uses a simple scenario where it creates an empty array and then fills it with 50 elements, each assigned the value `"lol"`.

**Options compared**

Two options are being compared:

1. **For loop**: A traditional `for` loop is used to iterate over the range of numbers from 0 to 49 (inclusive) and push the value `"lol"` onto the array.
2. **Map function**: The array `map()` method is used with an anonymous function that simply returns the value `"lol"`. This will apply the same transformation to each element in the array.

**Pros and Cons of each approach**

* **For loop**:
	+ Pros: Can be more intuitive for some developers, as it clearly shows the iteration process.
	+ Cons: Can lead to code bloat if not properly optimized (e.g., unnecessary variables or operations).
* **Map function**:
	+ Pros: Often faster and more concise than a `for` loop, especially when dealing with large datasets.
	+ Cons: Can be less intuitive for some developers who are not familiar with the `map()` method.

**Library**

In this benchmark, there is no explicit library mentioned. However, it's likely that the test case uses the built-in JavaScript features and functions to perform the comparison.

**Special JS feature or syntax**

There is one special feature used in this benchmark: **let` and `const` declarations**. These keywords are used to declare variables with block scope, which helps prevent variable hoisting issues.

**Other considerations**

When writing benchmarks like this one, it's essential to consider the following:

* Keep the test case simple and focused on the specific aspect being measured (in this case, performance difference between `for` loop and `map()`).
* Use a consistent naming convention and formatting throughout the benchmark.
* Ensure that the test case is representative of real-world use cases or scenarios.

**Other alternatives**

If you want to explore other approaches or optimizations for this benchmark, consider the following:

* Using an array with a fixed length instead of creating it dynamically using `Array(qty)`.
* Implementing the `for` loop and `map()` method with different optimization techniques (e.g., caching intermediate results or minimizing function call overhead).
* Adding additional test cases to cover other aspects, such as memory allocation, garbage collection, or parallel processing.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.125 Safari/537.36

Browser/OS: Chrome 84 on Mac OS X 10.15.6

View result in a separate tab

Test name	Executions per second
for	57819.8 Ops/sec
map	5468026.0 Ops/sec

Related benchmarks:

for vs map to fill array (version: 0)

Comparing performance of: for vs map

Created: 4 years ago by: Guest

Jump to the latest result

for

map

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):