Benchmark: Array spread operator vs push in reduce vs concat

Tests:

spread operator
var arr = [ { "opportunityId": 5943111, "findingList": [ { "findingId": 6919 } ], }, { "opportunityId": 5943111, "findingList": [ { "findingId": 6918, "findingId": 6917 } ] } ] arr.reduce((acc, findingInOpp) => [...acc, ...findingInOpp.findingList.map(({ findingId }) => findingId)],[])
Push
var arr = [ { "opportunityId": 5943111, "findingList": [ { "findingId": 6919 } ], }, { "opportunityId": 5943111, "findingList": [ { "findingId": 6918, "findingId": 6917 } ] } ] arr.reduce((acc, findingInOpp) => { acc.push(...findingInOpp.findingList.map(({ findingId }) => findingId)) return acc },[])
Concat
var arr = [ { "opportunityId": 5943111, "findingList": [ { "findingId": 6919 } ], }, { "opportunityId": 5943111, "findingList": [ { "findingId": 6918, "findingId": 6917 } ] } ] arr.reduce((acc, findingInOpp) => acc.concat(findingInOpp.findingList.map(({ findingId }) => findingId)),[])

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread operator
Push
Concat

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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Now, let's dive into the benchmark:

**Benchmark Definition**

The benchmark compares three approaches for flattening an array of objects with finding IDs:
1. Using the `Array.prototype.push` method inside a `reduce` function.
2. Using the new ES6 spread operator (`...`) to create a new array.
3. Using `Array.prototype.concat`.

**Options Compared**

Here's what each option does:

1. **Push**: Iterates over the `findingList` array and pushes each finding ID into the accumulator array using `push`. This approach modifies the original array.
2. **Spread Operator (`...`)**: Creates a new array by spreading the elements of the `findingList` array into it, effectively flattening it. This approach creates a new array without modifying the original one.
3. **Concat**: Concatenates the arrays using `concat`, which also creates a new array.

**Pros and Cons**

1. **Push**:
	* Pros: Simple to implement, may be faster since it modifies the original array (reduces memory allocation).
	* Cons: Modifies the original array, can lead to unexpected side effects.
2. **Spread Operator (`...`)**:
	* Pros: Creates a new array without modifying the original one, concise syntax.
	* Cons: May incur additional overhead for creating a new array.
3. **Concat**:
	* Pros: Also creates a new array without modifying the original one, can be more readable.
	* Cons: May incur additional overhead for concatenating arrays.

In general, `push` and `concat` are faster since they avoid creating a new array, but modify the original one. The spread operator is more concise but may incur additional overhead due to its nature of creating a new array.

**Library Used**

None in this benchmark definition.

**Special JS Features or Syntax**

The benchmark uses modern JavaScript features:
1. ES6 spread operator (`...`).
2. `Array.prototype.reduce`.
3. Modern array methods (e.g., `concat`, `push`).

Other Alternatives

If you want to explore other approaches, consider these alternatives:

* Using a library like Lodash or Ramda for array manipulation.
* Implementing a custom flattening function using recursion or iteration.
* Using a different data structure, such as a Set or Map, to store the finding IDs.

Keep in mind that each approach has its trade-offs and may be more suitable depending on your specific use case.

Related benchmarks:

Array spread operator vs push in reduce vs concat (version: 0)

Compare the new ES6 spread operator with push inside reduce vs concat

Comparing performance of: spread operator vs Push vs Concat

Created: 5 years ago by: Guest

Jump to the latest result

spread operator

Push

Concat

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):