Benchmark: UInt8Array vs cast to array index access 10k

Script Preparation code:

let arr = [];
for (let i = 0; i < 10000; i++)
    arr.push(i % 256);

var u8a = new Uint8Array(arr);

Tests:

Uint8Array index
const a = u8a; //(u8a as unknown) as number[]; const al = a.length; let s = 0; for(let i=0; i<al; i++) s += a[i];
Array.from array index
const a = Array.from(u8a); const al = a.length; let s = 0; for(let i=0; i<al; i++) s += a[i];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Uint8Array index
Array.from array index

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided benchmark compares the performance of two approaches to access elements in a Uint8Array:

1. **Direct Index Access**: The first test case uses direct indexing on the Uint8Array object, where `u8a[i]` is used to access each element. This approach is straightforward and native to JavaScript.
2. **Array.from() Method**: The second test case uses the Array.from() method to create an array from the Uint8Array object, and then iterates over this array using a for loop.

**Options Compared**

The benchmark compares the performance of these two approaches:

* Direct Index Access (using `u8a[i]`)
* Array.from() Method (to convert Uint8Array to an array)

**Pros and Cons of Each Approach**

1. **Direct Index Access**
	* Pros:
		+ Native to JavaScript, no additional libraries required.
		+ May be faster since it avoids the overhead of creating a new array.
	* Cons:
		+ Requires manual memory management (i.e., handling out-of-bounds indices).
2. **Array.from() Method**
	* Pros:
		+ Convenient and intuitive way to convert an array-like object to an actual array.
		+ Less prone to errors due to explicit bounds checking.
	* Cons:
		+ May incur additional overhead compared to direct indexing.

**Library Usage**

In this benchmark, the `Uint8Array` class is used as a native JavaScript object. No external libraries are required.

**Special JS Feature or Syntax**

There is no special JavaScript feature or syntax being tested in this benchmark.

**Other Alternatives**

If the Array.from() method is not available or preferred, other alternatives for converting an array-like object to an actual array include:

* `Array.prototype.slice.call()` (less efficient than Array.from())
* `new Array().push.apply(new Array(), u8a)` (more verbose)

However, in modern JavaScript, Array.from() is the recommended and most efficient way to achieve this conversion.

**Benchmark Result Interpretation**

The provided benchmark result shows the performance of each test case across multiple executions. The first test case performs better, with an execution rate of approximately 69101.25 executions per second, while the second test case has a lower execution rate (2463.099609375 executions per second). This suggests that direct indexing on the Uint8Array object is more efficient than using Array.from() in this specific benchmark.

Related benchmarks:

UInt8Array vs cast to array index access 10k (version: 0)

Comparing performance of: Uint8Array index vs Array.from array index

Created: 4 years ago by: Guest

Jump to the latest result

Uint8Array index

Array.from array index

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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