Benchmark: Spread operator vs forEach+Push

Tests:

spread operator
var params = [ "hello", true, 7 ] var other = [ 1, 2, ...params ]
Push
var params = [ "hello", true, 7 ]; var other = [ 1, 2 ]; params.forEach((param) => other.push(param));

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread operator
Push

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**What is tested?**

The benchmark compares two ways to create a new array in JavaScript: using the spread operator (`...`) and using the `forEach` method with `push`.

**Options compared:**

1. **Spread Operator (`...`)**: This allows you to extract elements from an existing array (or other iterable) into a new array.
2. **`forEach` method with `push`**: This involves iterating over an existing array using `forEach`, and then pushing each element onto a new array.

**Pros and Cons of each approach:**

1. **Spread Operator (`...`)**:
	* Pros: concise, readable, and efficient for small arrays.
	* Cons: may be slower than the `forEach` method with `push` for very large arrays.
2. **`forEach` method with `push`**:
	* Pros: more control over iteration and array growth, can handle large arrays efficiently.
	* Cons: less concise and readable compared to the spread operator.

**Library or special JS feature?**

Neither of these approaches requires any external libraries or special JavaScript features beyond what is included in a standard browser environment.

**Considerations:**

When choosing between these two approaches, consider the size of your array and the performance requirements of your application. For small arrays, the spread operator may be sufficient and more readable. However, for larger arrays, the `forEach` method with `push` might provide better performance.

**Other alternatives?**

If you need to create an array from a different iterable (e.g., a string or an object), you can use other methods like:

* `Array.from()`: creates a new array from an iterable.
* `slice()` and `concat()`: can also be used to create an array from an iterable, although they might not be as efficient as the spread operator.

The benchmark code provided by MeasureThat.net uses two individual test cases to compare these approaches. The first test case uses the spread operator with a small array of three elements: `"hello"`, `true`, and `7`. The second test case uses the `forEach` method with `push` to create an array from a smaller array.

Now that we've analyzed the benchmark, it's clear that the MeasureThat.net website is testing performance differences between two common ways to create arrays in JavaScript.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4780.0 Safari/537.36

Browser/OS: Chrome 99 on Linux

View result in a separate tab

Test name	Executions per second
spread operator	32328248.0 Ops/sec
Push	31991272.0 Ops/sec

Related benchmarks:

Spread operator vs forEach+Push (version: 0)

Compare the new ES6 spread operator with array push

Comparing performance of: spread operator vs Push

Created: 4 years ago by: Guest

Jump to the latest result

spread operator

Push

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):