Benchmark: push vs unshift - MeasureThat.net

Script Preparation code:

var arr = [];

Tests:

arrayPush-1
arr.push(1)
arrayUnshift-1
arr.unshift(1)
arrayConact-1
arr = [1, ...arr]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
arrayPush-1
arrayUnshift-1
arrayConact-1

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

I'd be happy to help you understand the JavaScript microbenchmarking test case on MeasureThat.net.

**Benchmark Overview**

The benchmark compares three different approaches for adding an element to an array in JavaScript:

1. `arr.push(1)`
2. `arr.unshift(1)`
3. `arr = [1, ...arr]`

**Approaches Compared**

Here's a brief description of each approach:

* **`arr.push(1)`**: This method adds the specified value to the end of the array.
* **`arr.unshift(1)`**: This method adds the specified value to the beginning of the array.
* **`arr = [1, ...arr]`**: This is a more modern approach using spread syntax. It creates a new array by concatenating the original array with the element `1`.

**Pros and Cons**

Here are some pros and cons for each approach:

* **`arr.push(1)`**:
	+ Pros: Simple, widely supported, efficient.
	+ Cons: Can be slower than other methods in some cases due to array resizing.
* **`arr.unshift(1)`**:
	+ Pros: Fastest method among the three, suitable for adding elements to the beginning of an array.
	+ Cons: Requires more memory allocation and copying when used with large arrays.
* **`arr = [1, ...arr]`**:
	+ Pros: Modern syntax, concise, and efficient for adding a single element.
	+ Cons: Can be slower than other methods for larger arrays due to the creation of a new array.

**Library Used**

None. This benchmark uses only built-in JavaScript features.

**Special JS Feature/Syntax**

The `...` spread operator used in the third approach (`arr = [1, ...arr]`) is a modern syntax introduced in ECMAScript 2015 (ES6). It's supported by most modern browsers and Node.js versions.

**Other Alternatives**

If you want to test other array operations or different algorithms, MeasureThat.net provides many benchmarks for various JavaScript scenarios. Some examples include:

* Array concatenation: `arr.concat([1])`
* Array slicing: `arr.slice(0, 10)`
* Array sorting and searching
* Object creation and comparison

Please note that the benchmark results may vary depending on the specific browser, device platform, operating system, and other factors.

Related benchmarks:

push vs unshift (version: 0)

push vs unshift

Comparing performance of: arrayPush-1 vs arrayUnshift-1 vs arrayConact-1

Created: 8 years ago by: Guest

Jump to the latest result

arrayPush-1

arrayUnshift-1

arrayConact-1

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):