Benchmark: array shift - array slice

Script Preparation code:

var array1 = Array(100).fill(1);
var array2;

Tests:

slice
array2 = array1.slice(1);
shift
array1.shift(); array2 = array1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
shift

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 provided benchmark and its individual test cases.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark, titled "array shift - array slice," tests two different approaches for shifting elements in an array: using `shift()` and using `slice()`. The goal of this benchmark is to determine which approach is faster.

**Script Preparation Code**

The script preparation code is:
```javascript
var array1 = Array(100).fill(1);
var array2;
```
This code creates a new array `array1` with 100 elements, all initialized to the value `1`. The variable `array2` is declared but not initialized.

**Html Preparation Code**

There is no HTML preparation code provided for this benchmark. This means that the benchmark only tests the JavaScript execution time and does not take into account any rendering or layout-related overhead.

**Individual Test Cases**

The benchmark consists of two test cases:

1. **"slice"**
```javascript
array2 = array1.slice(1);
```
This test case uses the `slice()` method to create a new array `array2` that includes all elements from `array1`, starting from the second element (index 1).

Pros of using `slice()`: It is generally considered a more modern and efficient way to create a subset of an array. `slice()` returns a shallow copy of the original array, which can be useful if you need to modify the resulting array.

Cons of using `slice()`: Creating a new array can be memory-intensive for large datasets. Additionally, `slice()` can be slower than other methods for small arrays because it involves creating a new array object.

2. **"shift"**
```javascript
array1.shift();
array2 = array1;
```
This test case uses the `shift()` method to remove the first element from `array1` and assigns the resulting array to `array2`.

Pros of using `shift()`: It is often faster than `slice()` because it modifies the original array in place, reducing memory allocations. However, `shift()` can be slower for large arrays due to its iterative nature.

Cons of using `shift()`: It can be less efficient than `slice()` because it involves modifying the original array, which may lead to additional overhead.

**Library and Special JS Features**

Neither test case uses any libraries or special JavaScript features beyond the standard language syntax. The focus is solely on comparing the performance of two basic array manipulation techniques.

**Other Alternatives**

Alternative methods for shifting elements in an array include:

* `unshift()`: Adds one or more elements to the beginning of an array.
* Array destructuring: Assigning values from an array to variables using destructuring syntax (e.g., `[a, b] = array;`).
* `forEach()` with a callback function: Iterating over an array and performing operations on each element.

These alternatives may have different performance characteristics compared to the `shift()` and `slice()` methods used in the benchmark.

Related benchmarks:

array shift - array slice (version: 0)

Comparing performance of: slice vs shift

Created: 4 years ago by: Guest

Jump to the latest result

slice

shift

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):