Benchmark: spread vs push set creation 2 fix

Tests:

spread
const a = [1,2,3]; const b = [4,5,6]; new Set([...a, ...b]);
push
const a = [1,2,3]; const b = [4,5,6]; const c = a; c.push(...b); new Set(c);

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Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
push

Fastest: N/A

Slowest: N/A

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

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Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is being tested?**

The benchmark measures the performance difference between two approaches for creating a new Set object from an array:

1. **Spread syntax**: The spread syntax `new Set([...a, ...b])` creates a new Set object by iterating over the elements of two arrays (`a` and `b`) and adding them to the set.
2. **Push with Set**: The push-based approach `const c = a; c.push(...b); new Set(c)` first assigns an array `c` to another variable, then pushes all elements from `b` into `c`, and finally creates a new Set object from the modified array.

**Options compared**

The benchmark compares two approaches:

* **Spread syntax**: This approach uses the spread operator (`...`) to create a new array with the concatenated elements of `a` and `b`.
* **Push with Set**: This approach involves creating an intermediate array by pushing all elements from `b` into another array `c`, which is initially assigned the value of `a`. The resulting array is then passed to the `Set` constructor.

**Pros and Cons**

**Spread syntax:**

Pros:

* Concise and readable code
* Does not create an intermediate array
* Can be faster due to fewer memory allocations

Cons:

* May have performance issues with large arrays or complex elements
* Can lead to unexpected behavior if used incorrectly (e.g., with non-array values)

**Push with Set:**

Pros:

* Can be more efficient for large arrays by avoiding excessive memory allocation and copying of small arrays
* Allows for better control over the intermediate array's size

Cons:

* More verbose code
* Creates an intermediate array, which can lead to performance issues if not properly managed
* May lead to unexpected behavior if used incorrectly (e.g., with non-array values)

**Other considerations**

When using `Set` in JavaScript, it's essential to consider the following factors:

* **Element type**: `Set` only works with unique elements. If you try to add duplicate elements, they will be ignored.
* **Iteration order**: The iteration order of a Set is not guaranteed and can vary depending on the browser or environment.
* **Performance**: Creating a new Set object from an array can be slower than other methods (e.g., using `map` or `Array.from`).

**Library usage**

In this benchmark, no libraries are explicitly used. However, if you're interested in exploring libraries that simplify working with Sets and arrays, some popular options include:

* Lodash's `lodash.set` function
* Array.prototype.reduce() or Array.prototype.forEach()
* Modern Array methods (e.g., `map()`, `filter()`, `forEach()`)

**Special JS features**

The benchmark uses the following special JavaScript feature:

* **Spread syntax (`...`)**: This is a shorthand for creating an array with all elements from another iterable. Introduced in ECMAScript 2015.

That's it! By understanding these concepts, you can better appreciate the performance differences between various approaches when working with Sets and arrays in JavaScript.

Related benchmarks:

spread vs push set creation 2 fix (version: 0)

Comparing performance of: spread vs push

Created: 5 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):