Benchmark: Push vs Spread Random

Script Preparation code:

arr = [];

Tests:

Spread
arr = [...arr, Math.random()];
Push
arr.push(Math.random());

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 its components.

**Benchmark Definition JSON**

The benchmark definition json contains information about the test being performed. The key fields are:

* `Name`: A unique name for the benchmark, which is "Push vs Spread Random" in this case.
* `Description`: An optional field that provides a brief description of the benchmark, but it's empty in this example.
* `Script Preparation Code` and `Html Preparation Code`: These fields provide code snippets that are executed before running the actual test. In this case, both fields are empty.

The script preparation code is used to initialize variables or set up the environment for the test. The "arr =[]" line creates an empty array in JavaScript.

**Individual Test Cases**

The benchmark defines two individual test cases:

* `Push`: This test case uses the `push()` method to add a random value to the end of the array.
* `Spread`: This test case uses the spread operator (`...`) to create a new array by adding a random value to the existing array.

Let's discuss each approach:

**`push()` vs `spread()`**

Both methods are used to add elements to an array, but they have different performance characteristics.

**`push()`**

The `push()` method is generally slower than the spread operator because it has to update the internal array length and create a new slot in the array. This process involves:

1. Updating the internal array length.
2. Creating a new slot for the added element.
3. Setting the new value at that slot.

In contrast, the spread operator (`...`) creates a new array by taking elements from the existing array and adding them to a new array. This approach is generally faster because it:

1. Creates a new array object without updating the internal array length.
2. Copies the elements from the original array into the new array.

**Pros and Cons**

* `push()`:
	+ Pros: Simple, widely supported, and easy to understand.
	+ Cons: Slower than the spread operator due to the update of internal array length and creation of a new slot.
* `spread()`:
	+ Pros: Generally faster because it creates a new array without updating the internal array length.
	+ Cons: May be less intuitive or harder to read for some developers, especially those not familiar with modern JavaScript features.

**Library and Special JS Features**

There are no libraries used in this benchmark. The test only uses built-in JavaScript methods (`push()` and `spread()`) and variables.

No special JS features are mentioned in the provided code snippets. However, if you're interested in exploring other performance-related techniques or optimizations, you might want to look into:

* Using typed arrays (e.g., `Uint8Array`, `Int32Array`)
* Optimizing array access patterns
* Leveraging browser-specific features like WebAssembly

**Other Alternatives**

If you wanted to explore alternative approaches for adding elements to an array, you could consider using other methods, such as:

* The `unshift()` method (similar to `push()`, but prepends the element instead of appending)
* `concat()` (a more explicit way of concatenating arrays)
* Using a library like Lodash's `assignIn` function
* Or even using a different data structure altogether, like an object or a linked list.

Related benchmarks:

Push vs Spread Random (version: 0)

Comparing performance of: Spread vs Push

Created: 7 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):