Benchmark: Set vs Filter for unique vs for

Script Preparation code:

var array = Array.from({length: 40}, () => Math.floor(Math.random() * 140));

var arrayA = Array.from({length: 40}, () => Math.random().toString(36).substring(2, 15));

Tests:

Set spread
const f = [... new Set(array)] const z = [... new Set(arrayA)]
Array from set
const s = new Set(array) const l = Array.from(s) const sa = new Set(array) const la = Array.from(sa)
Filter
const b = array.filter((i,index) => array.indexOf(i)=== index) const ba = arrayA.filter((i,index) => arrayA.indexOf(i)=== index)
Create Set
const ss = new Set(array) const sc = new Set(arrayA)
For
const s ={} const lc = [] for(let i =0; i < array.length; i++){ if (s[array[i]]) { continue } s[array[i]] = 1 lc.push(s[array[i]]) } const sa ={} const lca = [] for(let i =0; i < arrayA.length; i++){ if (s[arrayA[i]]) { continue } sa[arrayA[i]] = 1 lca.push(s[arrayA[i]]) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Set spread
Array from set
Filter
Create Set
For

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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Measuring performance of JavaScript operations is crucial for ensuring efficient and scalable code. Let's break down the provided benchmarking JSON.

**Benchmark Overview**
The test creates an array `array` with 40 random elements, each between 0 and 139 (inclusive). Another array `arrayA` is created with 40 random base64 encoded strings. These arrays are used to compare various JavaScript operations for creating a unique set.

**Options Compared**

1. **Set Spread**: Creating a new Set from the original array (`const f = [... new Set(array)]`) and then spreading it back into an array (`const z = [... new Set(array)]`).
2. **Array.from(Set)**: Creating a new Set from `array` and then using `Array.from()` to convert it back into an array (`const l = Array.from(s)`). The same approach is applied for `arrayA`.
3. **Filter**: Using the `filter()` method with a callback function that checks if the element's index in the original array matches its value (assuming no duplicates) (`const b = array.filter((i, index) => array.indexOf(i) === index)`).
4. **Create Set**: Creating a new Set directly from `array` and storing it in `ss`, then creating another Set directly from `arrayA` and storing it in `sc`.
5. **For Loop**: Using a loop to iterate over the arrays, checking for existing values in the `s` object (or its equivalent) before adding new ones.

**Pros and Cons of Each Approach**

1. **Set Spread**: Simple and efficient, as Set operations are optimized by JavaScript engines.
2. **Array.from(Set)**: Also efficient but may incur additional overhead due to converting between Set and Array.
3. **Filter**: May be slower due to the use of `indexOf()` which can lead to linear search in large arrays.
4. **Create Set**: Straightforward, yet may be slower than other methods as it involves direct Set creation and conversion.
5. **For Loop**: The loop approach is typically slower, especially for larger arrays, due to its inherent overhead.

**Library Usage**
The `Array.from()` method uses the native JavaScript API, which is implemented in the browser's engine (e.g., WebKit, Blink).

**Special JS Features or Syntax**

* None mentioned explicitly. However, some features like ES6 syntax (`const`, `let`, `=>`) are used implicitly.

**Alternatives**
Other alternatives to compare could include:

* Using `Map` instead of Sets
* Implementing custom data structures (e.g., hash tables) for faster lookups
* Using libraries like `lodash` which provide optimized implementations of Set-like operations

Related benchmarks:

Set vs Filter for unique vs for (version: 0)

Comparing performance of: Set spread vs Array from set vs Filter vs Create Set vs For

Created: 6 years ago by: Guest

Jump to the latest result

Set spread

Array from set

Filter

Create Set

For

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):