Benchmark: MyMy Spread vs Concat

Tests:

Spread Op
const a = ['se', 'fi', 'no', 'dk', 'nl', 'de', 'at', 'be', 'fr', 'pl'] const b = ['us', 'uk', 'au', 'es', 'it', 'ca', 'nz', 'pt', 'ie'] const c = [...a, ...b]
Concat
const a = ['se', 'fi', 'no', 'dk', 'nl', 'de', 'at', 'be', 'fr', 'pl'] const b = ['us', 'uk', 'au', 'es', 'it', 'ca', 'nz', 'pt', 'ie'] const c = [].concat(a, b)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread Op
Concat

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36

Browser/OS: Chrome 96 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Spread Op	13383105.0 Ops/sec
Concat	5415685.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring the performance of JavaScript operations is crucial in understanding the efficiency of various approaches and identifying potential bottlenecks in code.

**Benchmark Definition:**

The provided benchmark definition consists of two test cases:

1.  **Spread Operator (...)**: This approach uses the spread operator to concatenate arrays `a` and `b`. The syntax `c = [...a, ...b]` creates a new array by spreading the elements of `a` and `b`.
2.  **Concatenation using Array.prototype.concat()**: This approach uses the `concat()` method to concatenate arrays `a` and `b`. The syntax `c = [].concat(a, b)` returns a new array with the elements of `a` and `b`.

**Options Compared:**

The benchmark compares the performance of two approaches:

*   **Spread Operator (...)**: This approach is more concise and expressive but can be slower due to the overhead of creating a new array.
*   **Concatenation using Array.prototype.concat()**: This approach is more traditional and widely supported, but its syntax can be less readable.

**Pros and Cons:**

*   **Spread Operator (...)**
    *   Pros:
        *   More concise and expressive
        *   Can be faster for large arrays due to the use of a native operation
    *   Cons:
        *   Can be slower due to the overhead of creating a new array
*   **Concatenation using Array.prototype.concat()**
    *   Pros:
        *   More traditional and widely supported
        *   Can be faster for small arrays or when performance is critical
    *   Cons:
        *   Less concise and expressive
        *   Can be slower due to the use of a method call

**Library and Purpose:**

There are no libraries used in this benchmark. However, if we consider the `Array.prototype.concat()` method, it's part of the ECMAScript standard and is implemented by most JavaScript engines.

**Special JS Feature or Syntax:**

The benchmark uses the spread operator (`...`), which was introduced in ECMAScript 2015 (ES6). The syntax allows for more concise array creation and has become a popular choice among developers.

**Other Alternatives:**

Alternative approaches to concatenating arrays include:

*   Using `Array.prototype.push()` with an array as an argument, like this: `[...a, ...b].push(...a, ...b)`. This approach is less efficient than the spread operator but can be more readable.
*   Using a library or function that provides a custom concatenation method, such as Lodash's `concatAll()`.
*   Using a different data structure, like an array of objects, to avoid array concatenation altogether.

Keep in mind that these alternatives may have different trade-offs in terms of performance, readability, and maintainability.

Related benchmarks:

MyMy Spread vs Concat (version: 0)

Comparing performance of: Spread Op vs Concat

Created: 2 years ago by: Guest

Jump to the latest result

Spread Op

Concat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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