Benchmark: Array fill method vs for loop_

Tests:

For Loop fill
let arrayTest = new Array(10000000); for (let i = 0, l = arrayTest.length; i < l; ++i)arrayTest[i] = true;
Array Fill
let arrayTest = new Array(10000000).fill(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 25 days ago):

LLMs can make mistakes. Check important info.

I'd be happy to explain what's being tested in this benchmark.

The provided JSON represents a JavaScript microbenchmark that compares the performance of two approaches for filling an array: using a `for` loop and using the `fill()` method.

**Test Cases**

There are two test cases:

1. **For Loop fill**: This test case uses a traditional `for` loop to fill an array with 10 million elements with the value `true`.
2. **Array Fill**: This test case uses the `fill()` method to fill an array with 10 million elements with the value `true`.

**Comparison**

The benchmark aims to determine which approach is faster for filling a large array.

**Pros and Cons of Each Approach**

1. **For Loop fill**:
	* Pros: Generally more intuitive and easier to understand, as it's a familiar pattern from other programming languages.
	* Cons: Can be slower due to the overhead of incrementing the loop counter and checking the condition inside the loop.
2. **Array Fill**:
	* Pros: More concise and expressive, as it directly sets the value for each element in the array without explicit looping.
	* Cons: May have a slight performance penalty due to the creation of an internal buffer or other underlying optimizations.

**Other Considerations**

1. **Library Usage**: The `fill()` method is part of the ECMAScript Standard Library, which means it's implemented by most JavaScript engines and has good support for various optimization techniques.
2. **Special JS Features**: None mentioned in this benchmark, but if special features like `let` or `const` were used, they might impact performance due to additional overhead from variable hoisting or memory management.

**Other Alternatives**

If you're interested in exploring alternative approaches, some other methods for filling an array include:

1. **Array.prototype.forEach()**: A loop-free approach using the `forEach()` method.
2. **Array.prototype.map()**: A more concise approach using the `map()` method, which returns a new array with the values transformed or filled.

However, these alternatives might have slightly different performance characteristics and may not be as straightforward to understand as the `for` loop or `fill()` methods.

In summary, this benchmark aims to provide insights into the relative performance of two approaches for filling an array: traditional `for` looping versus using the `fill()` method.

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	11.5 Ops/sec
Array Fill	8.5 Ops/sec

Related benchmarks:

Array fill method vs for loop_ (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 25 days ago):