Benchmark: Concat vs push(...) for large arrays 2

Script Preparation code:

window.top.tests = {control:[], concat:[], spread:[]};
window.test = (new Array(10)).fill(null);
window.cutoff = 5000;

Tests:

Control (for push)
window.top.tests.control.push.apply(element, window.test); if (window.top.tests.control.length > window.cutoff) { window.top.tests.control = []; console.log('reset control'); }
Concat
window.top.tests.concat = window.top.tests.concat.concat(window.test); if (window.top.tests.concat.length > window.cutoff) { window.top.tests.concat = []; console.log('reset concat'); }
Spread
window.top.tests.spread.push(...window.test); if (window.top.tests.spread.length > window.cutoff) { window.top.tests.spread = []; console.log('reset spread'); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Control (for push)
Concat
Spread

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36

Browser/OS: Chrome 90 on Windows

View result in a separate tab

Test name	Executions per second
Control (for push)	0.0 Ops/sec
Concat	391671.0 Ops/sec
Spread	945893.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark test case and explain what is being tested.

**Benchmark Test Case**

The test case is comparing three different approaches to append to a large array: `push()`, `concat()`, and `spread()` methods.

**Options Being Compared**

* **`control.push.apply(element, window.test)`**: This approach uses the `apply()` method to apply the `push()` method to an array. The `element` parameter is not used in this test case.
* **`window.top.tests.concat.push(window.test)`**: This approach uses the `push()` method on an array created using the `concat()` method. In other words, a new array is created and then pushed with the original array.
* **`[...window.test].push(...)`**: This approach uses the spread operator (`...`) to create a new array from the original array, and then pushes elements onto it.

**Pros and Cons of Each Approach**

* **`control.push.apply(element, window.test)`**:
	+ Pros: Efficient in terms of memory allocation, as it modifies an existing array.
	+ Cons: May be slower due to the use of `apply()`, which can introduce additional overhead.
* **`window.top.tests.concat.push(window.test)`**:
	+ Pros: Can be faster than the first approach, as it creates a new array and then pushes elements onto it.
	+ Cons: Allocates more memory, as it creates a new array.
* **`[...window.test].push(...)`**:
	+ Pros: Most efficient in terms of memory allocation, as it creates a new array without modifying an existing one.
	+ Cons: May be slower due to the creation of a new array.

**Library and Purpose**

None are explicitly mentioned in this test case. However, `apply()` is a built-in JavaScript method that allows you to apply a function to a specific context or scope.

**Special JS Feature or Syntax**

The spread operator (`...`), which is used in the third approach, was introduced in ECMAScript 2015 (ES6) as a way to create new arrays from existing ones.

**Other Considerations**

* **Memory Allocation**: The test case highlights the importance of memory allocation when working with large arrays. Approaches that allocate more memory may have performance implications.
* **Cache Locality**: The use of `push()` on an array can improve cache locality, as it modifies a contiguous block of memory.

**Alternatives**

Other approaches to append to an array include:

* Using `Array.prototype.push()````
window.top.tests.control = window.top.tests.control.concat([window.test]);
```

This approach uses the `concat()` method to create a new array and then pushes elements onto it, similar to the second approach in the test case.

Related benchmarks:

Concat vs push(...) for large arrays 2 (version: 0)

Comparing the various ways to append to a large array

Comparing performance of: Control (for push) vs Concat vs Spread

Created: 3 years ago by: Guest

Jump to the latest result

Control (for push)

Concat

Spread

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):