Benchmark: Array.prototype.concat vs spread operator only

Tests:

Array.prototype.concat
var params = [ "hello", true, 7 ]; var other = [ 1, 2 ].concat(params);
spread operator
var params = [ "hello", true, 7 ] var other = [ 1, 2, ...params ]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data to understand what is being tested and compare different approaches.

**Benchmark Definition**

The benchmark compares two ways to concatenate arrays in JavaScript: the traditional `concat()` method and the new ES6 spread operator (`...`).

**Options Compared**

1. **Array.prototype.concat()**: The traditional way of concatenating arrays by using the `concat()` method on an instance of the Array prototype.
2. **Spread Operator (`...`)**: A newer syntax introduced in ECMAScript 2015 that allows spreading array elements into a new array.

**Pros and Cons**

*   **Array.prototype.concat()**:
    *   Pros: Widely supported, easy to understand, and compatible with older browsers.
    *   Cons: Can be slower and more memory-intensive than the spread operator due to its overhead.
*   **Spread Operator (`...`)**:
    *   Pros: More modern syntax, faster execution time, and less memory usage compared to `concat()`.
    *   Cons: May not be supported in older browsers or versions of JavaScript.

The spread operator is generally considered a better option for concatenating arrays due to its performance benefits. However, if compatibility with older browsers is essential, the traditional `concat()` method may still be used.

**Library and Its Purpose**

None are mentioned in this specific benchmark definition, but it's worth noting that other libraries or frameworks might use different methods or optimizations for array manipulation.

**Special JS Feature or Syntax (If applicable)**

The spread operator (`...`) is a relatively new feature introduced in ECMAScript 2015. It allows you to spread the elements of an array into a new array, creating a shallow copy. This syntax is not specific to any particular library but is part of the language standard.

**Other Alternatives**

If you need alternative approaches for concatenating arrays:

*   **Array.prototype.push()**: You can use `push()` method on an array instance instead of concatenating two arrays using the spread operator.
    ```javascript
var array = [1, 2];
array.push(3); // [1, 2, 3]
```
*   **String concatenation**: In some cases, you might consider string concatenation (`+`) as an alternative to array concatenation. However, be aware that this can lead to performance issues for large strings due to the creation of a new temporary string.
    ```javascript
var array = [1, 2];
var result = 'Hello '.concat(array.join(','));
```
Keep in mind that while these alternatives exist, they may not always provide better performance or compatibility compared to using the spread operator and `concat()` methods.

Overall, when choosing between `Array.prototype.concat()` and the spread operator (`...`), consider factors such as performance requirements, browser support, and code readability. The spread operator is generally a good choice for its balance of modernity and efficiency.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36

Browser/OS: Chrome 74 on Mac OS X 10.14.3

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	3361412.8 Ops/sec
spread operator	27174038.0 Ops/sec

Related benchmarks:

Array.prototype.concat vs spread operator only (version: 0)

Compare the new ES6 spread operator with the traditional concat() method

Comparing performance of: Array.prototype.concat vs spread operator

Created: 5 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):