Benchmark: js push vs spread

Tests:

spread
const items = [...Array(100).keys()] const newItems= [...items, 100]
push
const items = [...Array(100).keys()] items.push(100)

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:

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

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

**Benchmark Definition**

The benchmark is testing two approaches to create an array of numbers: using the spread operator (`...`) and pushing elements onto the end of the array.

**Options Compared**

The two options are:

1. `const items = [...Array(100).keys()]`: This approach uses the spread operator to create a new array with 100 elements, each initialized to a unique number from 0 to 99.
2. `items.push(100)`: This approach pushes a single element (the number 100) onto the end of an existing array.

**Pros and Cons**

1. **Spread Operator (`...`)**
	* Pros:
		+ Creates a new array, which can be more efficient if you need to modify or iterate over the entire array.
		+ Can be more readable and concise for creating arrays with multiple elements.
	* Cons:
		+ Requires JavaScript version 13+ for syntax support.
2. **Pushing Elements onto an Array (`items.push(100)` )**
	* Pros:
		+ Does not require creating a new array, which can save memory if you're working with large datasets.
	* Cons:
		+ Can be slower and less readable than the spread operator approach, especially for large arrays.

**Library/Functionality Used**

There is no specific library or function used in this benchmark. The `Array.prototype.keys()` method is a built-in JavaScript function that returns an iterator over the keys of the given array (in this case, an empty array with numbers from 0 to 99).

**Special JS Feature/Syntax**

The spread operator (`...`) was introduced in ECMAScript 2015 (ES6) and has since become a standard feature in modern JavaScript. It allows you to create new arrays by spreading the elements of an existing array or object.

**Other Alternatives**

If you didn't want to use the spread operator, you could also use `Array.from()` method, which creates a new array from an iterable (in this case, an empty array with numbers from 0 to 99). The syntax would be:
```javascript
const items = Array.from(Array(100).keys());
```
Alternatively, you could use the `map()` method to create a new array by applying a function to each element of an existing array:
```javascript
const items = [...Array(100).keys()].map((x) => x + 1);
```
However, these alternatives are generally less efficient and more verbose than using the spread operator.

Related benchmarks:

js push 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):