Benchmark: Array.flat() vs. concat() + spreadOperator vs. spreadOperator

Tests:

concat() + spread operator
var params = [[ 1, 2 ], [ "hello", true, 7 ]]; var other = [].concat(...params);
Array.flat()
var params = [[1, 2, params], [ "hello", true, 7 ]]; var other = params.flat();
spread operator
var params = [[ 1, 2 ], [ "hello", true, 7 ]]; var other = [...params];

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Suite status: <idle, ready to run>

Previous results

Test case name	Result
concat() + spread operator
Array.flat()
spread operator

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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!

The provided benchmark measures the performance of three different approaches to flatten an array:

1.  **`concat()` with the spread operator**: This approach uses the `concat()` method and the spread operator (`...`) to flatten the array.
2.  **`Array.flat()`:** This is a built-in JavaScript method introduced in ECMAScript 2019 that can be used to flatten arrays recursively.
3.  **The spread operator (`...`) alone**: This approach uses the spread operator to create a new array with all elements from the original array.

Now, let's discuss the pros and cons of each approach:

**`concat()` with the spread operator:**

Pros:

*   Well-supported by older browsers (Internet Explorer 11 and earlier).
*   Easy to understand for developers familiar with `concat()`.

Cons:

*   Less efficient than the other two approaches due to the overhead of calling `concat()` repeatedly.
*   May not work as expected in certain edge cases, such as arrays with nested arrays.

**`Array.flat()`:**

Pros:

*   Fast and efficient, making it a good choice for performance-critical code.
*   Works well with arrays of any depth and supports various options (e.g., `Infinity`, `1`, or `0`).

Cons:

*   Requires ECMAScript 2019 support (not available in older browsers).
*   May be less intuitive for developers unfamiliar with the method.

**The spread operator (`...`) alone:**

Pros:

*   Fast and efficient, similar to `Array.flat()`.
*   Widely supported by modern browsers and JavaScript engines.
*   Easy to understand for developers familiar with the spread operator.

Cons:

*   Requires ECMAScript 2015 support (not available in older browsers).
*   May not work as expected in certain edge cases, such as arrays with nested arrays.

**Library usage:**

The benchmark does not use any external libraries. The `Array.flat()` method is a built-in JavaScript function, and the spread operator (`...`) is a standard syntax feature introduced in ECMAScript 2015.

**Special JS features or syntax:**

This benchmark does not require any special JavaScript features or syntax beyond what's mentioned above (ECMAScript 2015 for the spread operator).

Now, let's look at some alternative approaches to flattening arrays:

*   **Using `reduce()`:** This approach uses the `reduce()` method to flatten an array. While it's a valid option, it may be less efficient than the other three methods.
*   **Using recursion:** This approach involves writing custom recursive functions to flatten an array. While it can work, it may be more prone to errors and is generally less efficient.
*   **Using `map()` and `concat`:** This approach uses `map()` to create a new array with flattened elements and then concatenates the resulting arrays using `concat()`. While it works, it's often less efficient than the other three methods.

Keep in mind that the choice of flattening method ultimately depends on your specific use case, performance requirements, and personal preference.

Related benchmarks:

Array.flat() vs. concat() + spreadOperator vs. spreadOperator (version: 0)

Compare the Array.flat() to concat() + spread operator

Comparing performance of: concat() + spread operator vs Array.flat() vs spread operator

Created: 5 years ago by: Guest

Jump to the latest result

concat() + spread operator

Array.flat()

spread operator

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):