Benchmark: Concat vs. Spread

Tests:

spread
const items = [ "one", "two", "three" ]; let items2 = []; for (var len = items.length, i = 0; i < len; i++){ items2 = [ ...items2, ...items[i] ]; }
push
const items = [ "one", "two", "three" ]; const items2 = []; for (var len = items.length, i = 0; i < len; i++){ items2.push(items[i]); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
push

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmarking data to understand what's being tested, compared, and the pros/cons of each approach.

**What is being tested?**

The provided benchmark measures the performance difference between two approaches:

1. Using the spread operator (`...`) to concatenate arrays.
2. Using the `push` method to add elements to an array.

**Options being compared:**

* **Spread Operator (Spreading)**: This involves using the spread operator (`...`) to create a new array by concatenating existing arrays.
```javascript
const items = [ "one", "two", "three" ];
let items2 = [];
for (var len = items.length, i = 0; i < len; i++) {
  items2 = [...items2, ...items[i]];
}
```
* **Push Method**: This involves using the `push` method to add elements to an existing array.
```javascript
const items = [ "one", "two", "three" ];
const items2 = [];
for (var len = items.length, i = 0; i < len; i++) {
  items2.push(items[i]);
}
```
**Pros/Cons of each approach:**

* **Spread Operator (Spreading)**:
	+ Pros:
		- More concise and expressive code.
		- Less error-prone than using `push` or other methods.
	+ Cons:
		- May incur additional overhead due to creating a new array and its associated memory allocation.
		- Can be slower for large datasets.
* **Push Method**:
	+ Pros:
		- Generally faster for large datasets, as it avoids the overhead of creating a new array.
		- More predictable performance, as the number of operations is fixed.
	+ Cons:
		- Requires explicit loop iteration or use of array methods like `forEach`.
		- May be less concise and more verbose than using the spread operator.

**Other considerations:**

* The benchmark uses JavaScript versions that are commonly used in modern web development (Chrome 108, Safari 537.36).
* The tests are run on a desktop platform with a specific operating system (Windows).

**Library usage:**

There is no explicit library usage mentioned in the provided benchmark definitions.

**Special JS feature or syntax:**

None of the benchmark cases use special JavaScript features or syntax that would require additional explanation.

**Alternatives:**

Other approaches for concatenating arrays could include:

* Using `Array.prototype.concat()` method.
* Creating a new array using `Array.from()` and then spreading it with the spread operator (`...`).
* Using other array methods, such as `reduce()`, to concatenate arrays.

These alternatives may offer different trade-offs in terms of performance, conciseness, and readability. However, without additional benchmarking data or context, it's difficult to determine which approach would be most suitable for a given use case.

Related benchmarks:

Concat vs. Spread (version: 0)

Comparing performance of: spread vs push

Created: 3 years ago by: Guest

Jump to the latest result

spread

push

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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