Benchmark: shift, unshift, concat

Script Preparation code:

var array = [1,2,3];

Tests:

shift
array.shift(0);
unshift
array.unshift(0);
concat
array = array.concat([0])

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
shift
unshift
concat

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):

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I'll do my best to explain the benchmark and its results.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The benchmark being discussed is designed to test the performance of three different methods for modifying an array: `shift`, `unshift`, and `concat`. These methods are commonly used in JavaScript for manipulating arrays, but their performance can vary depending on the browser and device.

**Benchmark Definition JSON**

The benchmark definition JSON contains the following information:

* `Name`: The name of the benchmark, which is "shift, unshift, concat".
* `Description`: An empty string, indicating that there is no description provided.
* `Script Preparation Code`: A script that initializes an array `array` with three elements: `[1, 2, 3]`.
* `Html Preparation Code`: An empty string, indicating that there is no HTML preparation code.

**Individual Test Cases**

The benchmark consists of three individual test cases:

* **shift**: Tests the performance of calling `array.shift(0)`, which removes and returns the first element from the array.
* **unshift**: Tests the performance of calling `array.unshift(0)`, which adds a new element to the beginning of the array.
* **concat**: Tests the performance of calling `array = array.concat([0])`, which creates a new array by concatenating the original array with a new element.

**Library Used**

None of the test cases use any external libraries. The tests only rely on built-in JavaScript methods and operations.

**Special JS Features or Syntax**

None of the test cases use any special JavaScript features or syntax beyond what is considered standard for JavaScript development.

**Performance Comparison**

The benchmark measures the performance of each method by executing it a large number of times (not specified in the provided data) and measuring the time taken to execute. The results are reported in milliseconds per execution.

Here's a brief summary of the results:

* **shift**: The fastest method, with an average execution time of approximately 7999 milliseconds per execution.
* **unshift**: Significantly slower than `shift`, with an average execution time of approximately 29449 milliseconds per execution.
* **concat**: The slowest method, with an average execution time of approximately 579 milliseconds per execution.

**Pros and Cons**

Here are some pros and cons for each method:

* **shift**:
	+ Pros: Fast and efficient, as it only requires a single operation to remove the first element from the array.
	+ Cons: Can be less intuitive and more error-prone than other methods.
* **unshift**:
	+ Pros: Allows for easier insertion of elements at the beginning of the array, but can be slower due to the need to create a new array.
	+ Cons: Slower than `shift`, especially for large arrays.
* **concat**:
	+ Pros: Can be used with existing code that requires concatenation, but is generally slower and less efficient.
	+ Cons: Creates a new array every time it's called, which can lead to increased memory usage.

**Alternatives**

Other alternatives for modifying arrays in JavaScript include:

* Using `splice()` instead of `shift` or `unshift`.
* Using `array.push()` instead of `concat`.
* Using `Array.prototype.slice()` instead of `concat`.

Each of these methods has its own trade-offs and performance characteristics, which may be worth considering depending on the specific use case.

Related benchmarks:

shift, unshift, concat (version: 0)

Comparing performance of: shift vs unshift vs concat

Created: 4 years ago by: Guest

Jump to the latest result

shift

unshift

concat

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):