Benchmark: Three ways of converting a JavaScript set to an array

Script Preparation code:

var set = new Set([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]);

Tests:

Array from
return Array.from(set);
Destructuring
return [...set]
forEach
let a = []; set.forEach(x => a.push(x)); return a;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array from
Destructuring
forEach

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 15 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser/OS: Chrome 135 on Windows

View result in a separate tab

Test name	Executions per second
Array from	29947180.0 Ops/sec
Destructuring	29028110.0 Ops/sec
forEach	7152086.5 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated 2 months ago):

LLMs can make mistakes. Check important info.

The benchmark defined by MeasureThat.net is focused on comparing three different methods of converting a JavaScript `Set` to an array. Using the provided JavaScript code, the benchmark evaluates three distinct approaches for this transformation, each with its own implications for performance and usability.

### Test Cases Explained

1. **Array from**: 
   - **Code**: `return Array.from(set);`
   - **Description**: This approach uses the built-in static method `Array.from()`. It takes an iterable (in this case, the `Set`) and returns a new Array instance containing the elements of the iterable.
   - **Pros**: 
     - Clear and concise syntax.
     - Handles various iterable types.
     - Supports an optional mapping function as a second argument.
   - **Cons**: 
     - Slight overhead compared to direct array constructions due to function call.

2. **Destructuring**: 
   - **Code**: `return [...set];`
   - **Description**: This method uses the spread operator (`...`), which spreads the elements of the `Set` into a new array.
   - **Pros**: 
     - Very succinct; allows for easy reading and quicker understanding of intent.
     - Executes efficiently as it internally creates an array without additional function calls.
   - **Cons**: 
     - Its behavior with non-iterables would throw an error, but that's less of a drawback when working with sets.

3. **forEach**: 
   - **Code**: `let a = []; set.forEach(x => a.push(x)); return a;`
   - **Description**: This approach manually initializes an empty array and pushes each element of the `Set` into it using the `forEach` method.
   - **Pros**: 
     - More explicit in its operations, which may be easier for beginners to understand.
     - Can be easily modified for more complex operations during the pushing phase.
   - **Cons**: 
     - Generally less efficient due to the required allocation of array space and multiple `push` calls, leading to more iterations and potential performance impact on larger sets.

### Benchmark Results

The benchmark results indicate the performance of each method in terms of executions per second:

- **Destructuring**: 24,273,112 executions/sec
- **Array from**: 23,342,888 executions/sec
- **forEach**: 6,131,639 executions/sec

From the execution counts, it’s evident that destructuring significantly outperforms both `Array.from()` and `forEach`, with the latter showing the lowest efficiency overall due to its iterative nature.

### Other Considerations

- **Performance**: The performance of destructuring and `Array.from()` is quite close, with destructuring having the edge. For large datasets or performance-critical applications, adopting destructuring is advisable when converting sets.
- **Readability vs. Efficiency**: While the `forEach` method may be easier for novices to comprehend, it sacrifices efficiency, especially in performance-sensitive applications.
- **Legacy Support**: It's worth noting that `Array.from()` and the spread operator are supported in modern JavaScript environments. If compatibility with older browsers is a concern, one might need to consider polyfills or fallback methods.

### Alternatives

Gravitating towards alternative ways of handling array conversions, a developer might consider the use of libraries or utility functions that can encapsulate these transformations, such as:

- **Lodash**: A utility library that provides robust methods for manipulation and conversion of data structures. For example, `_.toArray(set)` would convert the `Set` into an array.
- Native `map` or `reduce` methods for more complex transformations.
  
These alternatives introduce additional dependencies but offer greater flexibility or more utility features.

By understanding these variations and their performance traits, developers can make informed decisions based on their specific use cases and requirements.

Related benchmarks:

Three ways of converting a JavaScript set to an array (version: 1)

Comparing performance of: Array from vs Destructuring vs forEach

Created: 2 months ago by: Guest

Jump to the latest result

Array from

Destructuring

forEach

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated 2 months ago):