Benchmark: copy 3 - MeasureThat.net

Script Preparation code:

var proto_slice = Array.prototype.slice;
var a = [1,2,3];

Tests:

slice
Array.prototype.slice.call(a)
switch
switch (a.length) { case 0: return []; case 1: return [a[0]]; case 2: return [a[0], a[1]]; case 3: return [a[0], a[1], a[2]]; case 4: return [a[0], a[1], a[2], a[3]]; case 5: return [a[0], a[1], a[2], a[3], a[4]]; default: return proto_slice.call(a); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
switch

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.

I'll break down the benchmark test cases and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition JSON**

The provided JSON defines two benchmarks:

1. **Copy 3**: A simple benchmark that measures the performance of copying an array in JavaScript. It uses a prepared script (`var proto_slice = Array.prototype.slice;`) to initialize the `proto_slice` variable, which is used to call the `Array.prototype.slice()` method on an array `a`.
2. **Slice** and **Switch**: Two individual test cases that measure the performance of different operations:
	* **Slice**: Measures the performance of calling `Array.prototype.slice.call(a)` where `a` is an array.
	* **Switch**: Measures the performance of a `switch` statement with various cases, including some that return an empty array or a subset of the original array.

**Options Compared**

The benchmark compares two approaches for each test case:

1. **Copy 3**:
	* Using the `proto_slice` variable to call `Array.prototype.slice()` (with `call()`).
	* Not using `proto_slice` and calling `Array.prototype.slice()` directly.
2. **Slice**:
	* Using `Array.prototype.slice.call(a)` (the original implementation).
	* Using a custom implementation that calls `slice` with the array's length as an argument (`switch` statement).
3. **Switch**:
	* Using a traditional `switch` statement.
	* Using a simpler approach with only two cases, using the ternary operator (`a.length > 0 ? [a[0]] : []`).

**Pros and Cons of Each Approach**

Here's a brief overview of each approach:

1. **Copy 3 (using proto_slice)**:
	* Pros: Uses the built-in `Array.prototype.slice()` method, which is optimized for performance.
	* Cons: May incur additional overhead due to function call and object lookup.
2. **Copy 3 (not using proto_slice)**:
	* Pros: Avoids the overhead of a function call and object lookup.
	* Cons: May be slower than the built-in implementation.
3. **Slice** (original implementation):
	* Pros: Uses the optimized built-in `Array.prototype.slice()` method.
	* Cons: None notable.
4. **Slice** (custom implementation with switch statement):
	* Pros: May be faster due to reduced overhead and improved control flow.
	* Cons: More complex and may be less readable.
5. **Switch** (traditional implementation):
	* Pros: Easy to understand and maintain.
	* Cons: May be slower due to the additional logic.
6. **Switch** (simplified implementation with ternary operator):
	* Pros: Even faster than the traditional implementation, while still being easy to read.
	* Cons: Limited control flow and may not work as expected for all edge cases.

**Library Usage**

In the `Copy 3` benchmark, the `Array.prototype.slice()` method is used. This is a built-in JavaScript library function that's optimized for performance.

**Special JS Features/Syntax**

None of the provided benchmarks use any special JavaScript features or syntax.

**Other Alternatives**

If you want to explore alternative approaches, consider:

1. Using a custom implementation with a different data structure, such as a `slice` function that uses indexing instead of method calls.
2. Optimizing the built-in `Array.prototype.slice()` method using techniques like inlining or caching.
3. Using a different programming paradigm, such as using a loop instead of recursion.

Keep in mind that these alternatives might not be suitable for production code and should be used with caution.

Related benchmarks:

copy 3 (version: 0)

Comparing performance of: slice vs switch

Created: 9 years ago by: Guest

Jump to the latest result

slice

switch

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):