Benchmark: Bench arrays - MeasureThat.net

Script Preparation code:

var orig = [];
for (var i=0; i<10000; i++) {
  orig.push([i,i,i,i]);
}

Tests:

set
var next = []; for (var i=0, ito=orig.length; i<ito; i++) { var px = orig[i]; px[0]=i; px[1]=i; px[2]=i; px[3]=i; next.push(px); }
recreate
var next = []; for (var i=0, ito=orig.length; i<ito; i++) { var px = orig[i]; next.push([i,i,i,i]); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
set
recreate

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

I'll break down the provided JSON benchmark definition, test cases, and latest benchmark result.

**Benchmark Definition:**

The benchmark is designed to measure the performance of JavaScript arrays in two different scenarios:

1. **Pushing individual elements**: The script preparation code creates an array `orig` with 10,000 elements, where each element is a reference to another array with four elements (i.e., `[i,i,i,i]`). The test case "set" pushes these elements one by one into a new array `next`, updating the values of the individual elements in the process.
2. **Recreating arrays**: The script preparation code creates an array `orig` with 10,000 elements, where each element is another array with four elements (i.e., `[i,i,i,i]`). The test case "recreate" pushes these entire arrays into a new array `next`.

**Options compared:**

The two options being compared are:

1. **Pushing individual elements**: This approach involves updating the values of the individual elements in the array as they are pushed.
2. **Recreating arrays**: This approach involves pushing the entire array at once, without modifying its internal structure.

**Pros and Cons:**

* **Pushing individual elements**:
	+ Pros: May be more efficient for small to medium-sized arrays, as it only requires updating a few elements.
	+ Cons: Can be slower for large arrays due to the repeated updates.
* **Recreating arrays**:
	+ Pros: Typically faster for large arrays, as it involves fewer operations (pushing an entire array vs. pushing individual elements).
	+ Cons: May involve more memory allocation and garbage collection, potentially leading to slower performance.

**Test Cases:**

The two test cases are:

1. **set**: Pushes individual elements into the `next` array.
2. **recreate**: Pushes entire arrays into the `next` array.

**Library/Technology Used:**

No specific library or technology is mentioned in the benchmark definition, but it appears to be running on a JavaScript engine (e.g., SpiderMonkey for Firefox).

**Special JS Feature/Syntax:**

None are explicitly mentioned, but the use of `var` and `for` loops indicates that this benchmark is compatible with older versions of JavaScript.

**Other Considerations:**

When comparing the performance of these two approaches, it's essential to consider factors such as:

* Array size: The impact of pushing individual elements vs. recreating arrays becomes more pronounced for larger array sizes.
* Memory constraints: If memory allocation and garbage collection are critical, recreating arrays might be a better choice.
* Performance requirements: For applications requiring fast data insertion and modification, the chosen approach should prioritize execution speed.

**Alternatives:**

Other alternatives to consider when benchmarking JavaScript array performance include:

1. **Using `push` with an array initializer**: Instead of pushing individual elements, use `push` with an array initializer to create a new array.
2. **Using `Array.from()` or `spread operator`**: Use `Array.from()` or the spread operator (`...`) to push entire arrays into the target array.
3. **Using `slice()` or `subarray()`**: Instead of pushing individual elements, use `slice()` or `subarray()` to extract a subset of elements from the original array.

Keep in mind that these alternatives might have different performance characteristics and trade-offs depending on the specific use case and JavaScript engine being used.

Related benchmarks:

Bench arrays (version: 0)

Comparing performance of: set vs recreate

Created: 8 years ago by: Guest

Jump to the latest result

set

recreate

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):