Benchmark: Array.prototype.push vs Array.prototype.push.apply2

Script Preparation code:

var arr1 = Array(100).fill([{n: ''}]);
var arr2 = Array(100).fill([{n: ''}]);

Tests:

Array.prototype.push.apply
Array.prototype.push.apply(arr1, arr2)
Array.prototype.push
arr1.push(...arr2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.push.apply
Array.prototype.push

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_2) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.4 Safari/605.1.15

Browser/OS: Safari 13 on Mac OS X 10.15.2

View result in a separate tab

Test name	Executions per second
Array.prototype.push.apply	431465.6 Ops/sec
Array.prototype.push	25858.3 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided JSON represents a benchmark test for comparing the performance of two approaches to add elements to an array: `Array.prototype.push.apply` and `Array.prototype.push`.

**Options Compared**

*   `Array.prototype.push.apply(arr1, arr2)`: This method applies an array to `push`. In this case, it uses the spread operator (`arr2`) as the array to be applied.
*   `arr1.push(...arr2)`: This method uses the spread operator (`...arr2`) to unpack the elements of `arr2` and add them one by one to `arr1`.

**Pros and Cons**

*   `Array.prototype.push.apply(arr1, arr2)`:
    *   Pros:
        *   Can be more efficient for large arrays since it can use a more optimized algorithm under the hood.
        *   Does not create an intermediate array, which can reduce memory usage.
    *   Cons:
        *   May have slower performance due to the additional overhead of applying the array to `push`.
*   `arr1.push(...arr2)`: 
    *   Pros:
        *   Easier to read and maintain than `Array.prototype.push.apply`.
        *   Does not require an additional function call or array creation.
    *   Cons:
        *   May be slower due to the overhead of unpacking and adding each element individually.

**Library and Purpose**

In this benchmark, no libraries are explicitly mentioned. However, it's worth noting that the use of modern JavaScript features like spread operators (`...`) is often dependent on library support or implementation-specific behavior.

**Special JS Feature/Syntax**

The benchmark uses the spread operator (`...`) to unpack elements from an array into a new array. This syntax was introduced in ECMAScript 2015 (ES6) and has been widely adopted since then.

**Other Alternatives**

Alternative approaches could include:

*   Using `Array.prototype.concat()` instead of spread operators.
*   Creating an intermediate array using `Array.from()` and pushing elements to it, then assigning the result back to `arr1`.
*   Using a library like Lodash's `_.unionBy` or `_.merge` to concatenate arrays.

These alternatives would change the fundamental approach to adding elements to an array and might not be as efficient or readable as the original methods.

Related benchmarks:

Array.prototype.push vs Array.prototype.push.apply2 (version: 0)

Comparing performance of: Array.prototype.push.apply vs Array.prototype.push

Created: 4 years ago by: Guest

Jump to the latest result

Array.prototype.push.apply

Array.prototype.push

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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