Benchmark: Slice & reverse vs Loop & unshift

Script Preparation code:


var arr = ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10'];

Tests:

slice & reverse
var x = arr.slice(0,5).reverse(); var y = arr.slice(6, 9);
loop & unshift
var x = []; var y = []; var current = 5 for(i=1; i<9; i++){ if (i<=current) { x.unshift(i); } else { y.push(i); } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice & reverse
loop & unshift

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the benchmark and its test cases.

**Benchmark Definition**

The benchmark measures the performance difference between two approaches: slicing an array, reversing it, and then slicing again (Slice & Reverse), versus using a loop to append elements to a new array while shifting the original array (Loop & Unshift).

**Options Compared**

The benchmark compares two different algorithms:

1. **Slice & Reverse**: This approach slices the original array into two parts at indices 0-5 and 6-9, reverses the first part, and then assigns it back to `x`. The second part is assigned to `y`.
2. **Loop & Unshift**: This approach creates two empty arrays `x` and `y`, initializes a variable `current` to 5, and then uses a loop to append elements to `x` if they are less than or equal to `current`, and push them onto `y` otherwise.

**Pros and Cons of Each Approach**

* **Slice & Reverse**
	+ Pros:
		- More concise and readable code
		- Less memory allocation and deallocation overhead
	- Cons:
		- May not be as efficient for large arrays due to the overhead of slicing and reversing
* **Loop & Unshift**
	+ Pros:
		- Can be more efficient for large arrays due to minimizing array allocations and shifts
	+ Cons:
		- More verbose and less readable code

**Library Usage**

None of the test cases use any external libraries.

**Special JS Features/Syntax**

None of the test cases employ any special JavaScript features or syntax.

**Other Alternatives**

Other possible approaches could include:

* Using `Array.prototype.map()` to create a new array with the desired elements
* Using `Array.prototype.reduce()` to accumulate elements in an array
* Using `Array.prototype.concat()` and `Array.prototype.splice()` to manipulate arrays

However, these alternatives would likely introduce additional overhead and may not provide any significant performance benefits over the original Slice & Reverse and Loop & Unshift approaches.

**Benchmark Preparation Code**

The provided benchmark preparation code creates a sample array `arr` with 10 elements and assigns it to the `x` variable. The `Script Preparation Code` section is empty, indicating that no additional setup or processing is required before running the benchmarks.

**Individual Test Cases**

Each test case consists of two parts:

1. A **Benchmark Definition** string that describes the algorithm to be tested.
2. A **Test Name** string that identifies the specific benchmark being executed.

The first test case measures the performance difference between Slice & Reverse and Loop & Unshift for reversing an array, while the second test case measures the performance difference between these two approaches for appending elements to a new array while shifting the original array.

Related benchmarks:

Slice & reverse vs Loop & unshift (version: 0)

Comparing performance of: slice & reverse vs loop & unshift

Created: 4 years ago by: Guest

Jump to the latest result

slice & reverse

loop & unshift

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):