Benchmark: flat vs concat (simplest) vs spread

Script Preparation code:

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
var test = []
for (let i = 0; i < 1000; i++) {
  test.push(arr)
}

Tests:

flatMap
var flatten = test.flatMap((x) => x)
concat
var catten = []; var size = test.length for (let k = 0; k < size; k++) { catten = catten.concat(test[k]) }
spread
var catten = []; var size = test.length for (let k = 0; k < size; k++) { catten = [...catten, ...test[k]] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
flatMap
concat
spread

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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Let's break down the provided benchmark and explain what's being tested.

**Benchmark Definition JSON**

The provided JSON represents a JavaScript benchmark that compares three different ways to concatenate an array of arrays:

1. `flatMap`
2. `concat`
3. `spread`

The script preparation code creates an array `arr` with 10 elements, which will be used as the input for each test case.

**Test Cases**

There are three individual test cases, each with a different approach to concatenate the array of arrays:

1. **flatMap**: This method is part of the Array.prototype method and is used to create a new array by applying a given function to each element of an array. In this case, it's used to flatten the array of arrays.
2. **concat**: This method is also part of the Array.prototype method and is used to concatenate two or more arrays. It creates a new array with all elements from the original arrays.
3. **spread**: This syntax uses the spread operator (`...`) to expand an array into individual elements. In this case, it's used to concatenate the array of arrays by spreading each inner array into the outer one.

**Options Compared**

The three test cases are compared in terms of performance:

* `flatMap` vs `concat`
* `concat` vs `spread`

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

1. **flatMap**:
	* Pros: More concise, potentially faster due to reduced overhead.
	* Cons: May not be as efficient for large arrays or complex transformations.
2. **concat**:
	* Pros: Widely supported, easy to understand.
	* Cons: Can be slower than `flatMap` due to the creation of a new array.
3. **spread**:
	* Pros: Concise and expressive, potentially faster due to reduced overhead.
	* Cons: May not be as efficient for large arrays or complex transformations.

**Library Usage**

None of the test cases use any external libraries.

**Special JS Features/Syntax**

None of the test cases use any special JavaScript features or syntax beyond what's normally available in modern browsers.

**Other Alternatives**

If you're interested in exploring alternative approaches, here are a few options:

* Using `reduce()` instead of `flatMap` and `concat`.
* Using a custom loop instead of the built-in array methods.
* Using a different language or framework for benchmarking (e.g., Rust, Python).

Keep in mind that these alternatives might not be directly comparable to the original test cases, as they would require significant modifications to the benchmark code.

Related benchmarks:

flat vs concat (simplest) vs spread (version: 0)

Comparing performance of: flatMap vs concat vs spread

Created: 3 years ago by: Guest

Jump to the latest result

flatMap

concat

spread

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):