Benchmark: Array .push() vs spread operator

Tests:

.push()
const arr = [1,2]; arr.push(3);
spread operator
let arr = [1,2]; arr = [...arr, 3];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
.push()
spread operator

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.5112.81 Safari/537.36 Edg/104.0.1293.47

Browser/OS: Chrome 104 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
.push()	91445056.0 Ops/sec
spread operator	55066828.0 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 and its test cases.

**Benchmark Definition**
The benchmark is defined as "Array .push() vs spread operator". This means that the benchmark compares the performance of two different approaches:

1. Using the `.push()` method to add an element to an array.
2. Using the spread operator (`...`) to create a new array with the original elements and the newly added element.

**Options Compared**

The two options being compared are:

* **`.push()`**: The `push()` method is a built-in JavaScript method that adds one or more elements to the end of an array.
* **Spread Operator (`...`)**: The spread operator is used to create a new array by copying elements from an existing array. In this case, it's used to add a single element to the original array.

**Pros and Cons**

* **`.push()`**: Pros:
	+ Widely supported in older browsers.
	+ Can be more efficient for large arrays since it doesn't require creating a new array.
	Cons:
	+ Can be slower than the spread operator for small arrays due to the overhead of adding elements to the end of the array.
* **Spread Operator (`...`)**: Pros:
	+ Can be faster than `.push()` for small arrays since it creates a new array with the newly added element, which can lead to less memory allocation and copying.
	Cons:
	+ Requires modern browsers that support the spread operator.

**Library and Syntax Considerations**

There is no library being used in this benchmark. The only syntax-related consideration is the use of the `const` keyword for variable declarations, which is a feature introduced in ECMAScript 2015 (ES6). However, since both test cases are using modern JavaScript syntax, this shouldn't be an issue.

**Other Alternatives**

If you wanted to compare other approaches for adding elements to an array, you could consider:

* Using the `unshift()` method instead of `.push()`.
* Creating a new array and assigning it to a new variable using the spread operator.
* Using a library like Lodash's `assignIn` function.

For example, an additional test case could compare the performance of `.push()` versus creating a new array using the spread operator:
```json
{
    "Benchmark Definition": "let arr = [1,2];\r\nconst newArr = [...arr, 3];",
    "Test Name": ".unshift() vs array creation"
}
```
This would allow you to compare the performance of `.push()` versus creating a new array using the spread operator.

Related benchmarks:

Array .push() vs spread operator (version: 0)

Comparing performance of: .push() vs spread operator

Created: 2 years ago by: Guest

Jump to the latest result

.push()

spread operator

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):