Benchmark: Array.prototype.push vs Spread operator

Tests:

Array.prototype.push
let a = [] a.push(1)
Spread
let a = [] a = [...a, 1]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.push
Spread

Fastest: N/A

Slowest: N/A

Latest run results:

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

LLMs can make mistakes. Check important info.

I'd be happy to explain what's being tested in this benchmark.

**What is being tested?**

The provided JSON represents two individual test cases for measuring the performance of JavaScript microbenchmarks. The benchmarks compare the execution times of two approaches:

1. `Array.prototype.push`: This approach uses the `push()` method to add elements to an empty array.
2. Spread operator (`...a, 1`): This approach uses the spread operator to create a new array with the existing elements and then adds a new element.

**Options compared**

The benchmark is comparing two options:

* Using the `Array.prototype.push()` method to add an element to an array.
* Using the spread operator (`...`) to create a new array with existing elements and then adding a new element.

**Pros and cons of each approach:**

1. **`Array.prototype.push()`**:
	* Pros:
		+ Wide browser support
		+ Efficient for large arrays (since it only updates the length property)
		+ Less memory allocation compared to creating a new array with spread operator
	* Cons:
		+ May not be as efficient for small arrays or when adding a single element
		+ Can lead to unnecessary memory reallocation if not implemented correctly
2. **Spread operator (`...`)**:
	* Pros:
		+ More concise and readable code
		+ Can create a new array without modifying the original one
		+ Efficient for small arrays or when adding a single element
	* Cons:
		+ May incur additional memory allocation due to creating a new array
		+ Less efficient than `Array.prototype.push()` for large arrays

**Library and its purpose**

There is no specific library mentioned in the provided JSON. However, both approaches use native JavaScript features:

1. **`Array.prototype.push()`**: This method is part of the Array prototype in JavaScript.
2. Spread operator (`...`): This operator is a built-in feature in modern JavaScript.

**Special JS features or syntax**

There are no special JavaScript features or syntax mentioned in the provided JSON. Both approaches use standard JavaScript methods and operators.

**Other alternatives**

If you were to rewrite this benchmark, other alternatives could include:

1. Using `Array.concat()` instead of spread operator
2. Creating a new array using the `Array` constructor (`new Array(0).push(1)`)
3. Comparing the performance with different array lengths (e.g., 100 elements, 1000 elements)

These alternative approaches would allow you to explore more variations and compare their performance in this benchmark.

**Benchmark preparation code**

The provided JSON includes two script preparation codes:

```javascript
let a = [];
a.push(1);
```

and

```javascript
let a = [];
a = [...a, 1];
```

These codes are used as the starting points for the benchmark measurements.

Related benchmarks:

Array.prototype.push vs Spread operator (version: 0)

Comparing performance of: Array.prototype.push vs Spread

Created: 5 years ago by: Guest

Jump to the latest result

Array.prototype.push

Spread

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):