Benchmark: Array.prototype.concat vs spread operator - multiple array

Tests:

Array.prototype.concat
const arr1 = [ "hello", true, 7 ]; const arr2 = [ "world", false, 0]; const arr3 = [ "testing", 1, 2 , 3]; const other = arr1.concat(arr2).concat(arr3);
spread operator
const arr1 = [ "hello", true, 7 ]; const arr2 = [ "world", false, 0]; const arr3 = [ "testing", 1, 2 , 3]; const other = [...arr1, ...arr2, ...arr3];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator

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 benchmark.

The provided JSON represents a JavaScript microbenchmark that compares two approaches for concatenating arrays: `Array.prototype.concat` and the spread operator (`...`). This benchmark is testing the performance of these two methods on multiple arrays.

**What are being compared?**

In the first test case, the `concat()` method is used to concatenate three arrays (`arr1`, `arr2`, and `arr3`) into a single array called `other`. In contrast, the second test case uses the spread operator (`...`) to achieve the same result.

**Pros and Cons of each approach:**

1. **Array.prototype.concat()**:
	* Pros: This method is well-established and widely supported by browsers.
	* Cons: It's a slower operation compared to the spread operator, as it creates an intermediate array that needs to be traversed.
2. **Spread operator (`...`)**:
	* Pros: The spread operator is generally faster than `concat()`, as it avoids creating an intermediate array and directly returns the concatenated array.
	* Cons: It's a relatively new feature introduced in ES6, so its support might vary across browsers.

The choice between these two methods depends on performance requirements and compatibility considerations. If you need to support older browsers or require a simple concatenation operation, `concat()` might be a better choice. However, for modern web applications where speed is crucial, the spread operator is likely a better option.

**Library usage:**

There are no libraries used in this benchmark.

**Special JS feature or syntax:**

The benchmark uses the spread operator (`...`), which is a new JavaScript feature introduced in ES6. The `concat()` method, on the other hand, is a standard array method that's been part of JavaScript since its inception.

**Other alternatives:**

1. **Array.prototype.push()**: This method appends elements to an existing array and returns the length of the resulting array. While it can be used for concatenation, it's generally slower than `concat()` or the spread operator.
2. **Array.prototype.set()**: This method sets multiple elements in an existing array. Again, while it can be used for concatenation, it's not as efficient as the other two options.

Keep in mind that these alternatives are not recommended for use in performance-critical code or when working with large datasets.

Related benchmarks:

Array.prototype.concat vs spread operator - multiple array (version: 0)

Compare the new ES6 spread operator with the traditional concat() method

Comparing performance of: Array.prototype.concat vs spread operator

Created: 2 years ago by: Guest

Jump to the latest result

Array.prototype.concat

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):