Benchmark: Array fill method vs for loop__w

Tests:

For Loop fill
let len = 100; let arrayTest = []; arrayTest.length = len; for (let i = 0; i < len; ++i)arrayTest[i] = true;
Array Fill
let arrayTest = new Array(100); let len = arrayTest.length; for (let i = 0; i < len; ++i)arrayTest[i] = true;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
For Loop fill
Array Fill

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is comparing two approaches to populate an array with a fixed length:

1. **For Loop**: Using a traditional for loop to iterate over the array index and assign a value (in this case, `true`) to each element.
2. **Array Fill**: Using the `length` property of the array to set its size, and then using the `new Array()` constructor or assignment operator (`=[])` to initialize the array with a specified length.

**Comparison**

The benchmark is comparing the performance of these two approaches on various JavaScript engines.

**Pros and Cons**

**For Loop:**

Pros:

* Easy to understand and implement
* Can be used in a variety of contexts

Cons:

* May incur overhead due to loop control logic
* May have issues with array indexing and bounds checking

**Array Fill:**

Pros:

* Fast and efficient, as it avoids loop control logic
* Provides a convenient way to set the length of an array

Cons:

* Less intuitive for some developers
* May not work in older browsers or environments that don't support modern JavaScript features.

**Other Considerations**

* The benchmark doesn't account for other factors like memory allocation, garbage collection, or caching. These can impact performance and should be considered when optimizing code.
* The benchmark is specific to the Chrome 91 browser and Windows 8.1 operating system. Results may vary on different platforms and browsers.

**Library and JavaScript Feature**

There is no library being used in this benchmark, but it does rely on a modern JavaScript feature: the `let` and `const` declarations, which are part of the ECMAScript 2015 (ES6) standard.

**Alternative Approaches**

Other approaches to populate an array with a fixed length include:

1. Using the `Array.prototype.fill()` method
2. Utilizing a library like Lodash or Ramda for efficient array manipulation

These alternatives may offer different trade-offs in terms of performance, readability, and compatibility with older browsers.

**Additional Notes**

The benchmark results show that the For Loop approach is slightly faster than the Array Fill approach on this specific test case. However, the difference is relatively small, and both approaches should be considered suitable for most use cases.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.106 Safari/537.36

Browser/OS: Chrome 91 on Windows 8.1

View result in a separate tab

Test name	Executions per second
For Loop fill	984827.4 Ops/sec
Array Fill	949596.9 Ops/sec

Related benchmarks:

Array fill method vs for loop__w (version: 0)

Array fill method vs for loop performance validation

Comparing performance of: For Loop fill vs Array Fill

Created: 3 years ago by: Guest

Jump to the latest result

For Loop fill

Array Fill

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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