Benchmark: set.add vs. array.push

Script Preparation code:

var a = Array.from({length: 100000}, () => Math.floor(Math.random() * 40));
var b = new Set(a);

Tests:

Push
a.push(191818);
Add
b.add(191818);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Push
Add

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36 Edg/137.0.0.0

Browser/OS: Chrome 137 on Windows

View result in a separate tab

Push

12.2M/s

Add

10.0M/s

View exact numbers

Test name	Executions per second
✓ Push	12,228,769 Ops/sec
Add	10,020,596 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases.

**Benchmark Definition**
The benchmark measures the performance difference between using `set.add` versus `array.push` in JavaScript. The script preparation code initializes two arrays of size 100,000 with random values between 0 and 39. It then creates a new Set object from the first array (`b = new Set(a)`).

**Script Preparation Code**
```javascript
var a = Array.from({length: 100000}, () => Math.floor(Math.random() * 40));
var b = new Set(a);
```
This code creates an array `a` with 100,000 elements and populates it with random values between 0 and 39. It then creates a new Set object `b` from the array.

**Individual Test Cases**
There are two test cases:

1. **Push**: Measures the performance of using `array.push(191818)` on the original array `a`.
2. **Add**: Measures the performance of using `set.add(191818)` on the Set object `b`.

**Libraries and Special JS Features**

* The `Array.from()` method is used to create a new array from an iterable (in this case, an object with a `length` property).
* There are no libraries mentioned in the benchmark definition.
* No special JavaScript features or syntax are used in this benchmark.

Now, let's discuss the pros and cons of each approach:

**Array.push()**

Pros:

* Fast and efficient when adding elements to the end of an array.
* Suitable for large arrays where random access is required.

Cons:

* Can lead to memory fragmentation if elements are added at arbitrary indices.
* May cause performance issues due to the need to update internal array metadata.

**Set.add()**

Pros:

* Fast and efficient when adding unique elements to a set.
* Ensures uniqueness of elements, which can be beneficial in certain use cases.

Cons:

* Can lead to slower performance for large sets or sets with many duplicate elements.
* May not be suitable for use cases where random access is required.

**Considerations**

When choosing between `array.push()` and `set.add()`, consider the following factors:

* **Performance**: If you need fast insertion of unique elements, `set.add()` might be a better choice. However, if you require random access to elements in the array or set, `array.push()` might be more suitable.
* **Memory usage**: If memory is limited, `array.push()` might lead to increased memory fragmentation, while `set.add()` can help reduce memory usage by avoiding duplicate elements.

**Alternatives**

Other alternatives for adding elements to an array or set include:

* Using `push()` with a new element, e.g., `a.push(newElement)`.
* Using the spread operator (`...`) to create a new array from an existing one, e.g., `newArray = [...a, newElement]`.
* Using `Array.prototype.concat()` to concatenate two arrays, e.g., `a = a.concat([newElement])`.

Keep in mind that these alternatives may have different performance characteristics and memory usage compared to `array.push()` and `set.add()`.

set.add vs. array.push (version: 0)

set.add vs. array.push

Comparing performance of: `Push vs Add`

Created: 4 years ago by: Guest

Go to the latest result

Push

Add

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

set.add vs. array.push (version: 0)

set.add vs. array.push

Comparing performance of: Push vs Add

Created: 4 years ago by: Guest

Go to the latest result

Push

Add

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Comparing performance of: `Push vs Add`