Benchmark: Array concat vs spread operator vs loop push

Tests:

Array.prototype.concat
var params = [ "hello", true, 7 ]; var other = [ 1, 2 ].concat(params);
spread operator
var params = [ "hello", true, 7 ] var other = [ 1, 2, ...params ]
Push
var params = [ "hello", true, 7 ]; var other = [ 1, 2 ]; for (var index of params) { other.push(index); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.prototype.concat
spread operator
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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**Overview of the Benchmark**

The provided benchmark compares three approaches to concatenate an array in JavaScript:

1. **Array.prototype.concat()**: The traditional method of concatenating arrays using the `concat()` method.
2. **Spread Operator (`...`)**: A new feature introduced in ES6 that allows for spreading the elements of an array into a new array.
3. **Manual Loop**: Using a loop to push each element from one array into another.

**Options Compared**

The benchmark compares these three approaches, measuring their performance and execution time.

**Pros and Cons of Each Approach**

1. **Array.prototype.concat()**
	* Pros:
		+ Widely supported and well-documented.
		+ Easy to understand for developers familiar with this method.
	* Cons:
		+ Can be slower than other methods due to its overhead.
		+ Does not take advantage of modern hardware capabilities like SIMD (Single Instruction, Multiple Data).
2. **Spread Operator (`...`)**
	* Pros:
		+ Fast and efficient for small arrays.
		+ Modern JavaScript syntax.
		+ Compatible with most browsers.
	* Cons:
		+ May require more time to understand for developers unfamiliar with this feature.
		+ Not supported in older browsers (e.g., IE 11).
3. **Manual Loop**
	* Pros:
		+ Allows for direct control over the iteration process.
		+ Can be faster than other methods for very large arrays.
	* Cons:
		+ Requires manual handling of iteration and indexing.
		+ Less readable and maintainable.

**Library Used**

None explicitly mentioned, but it is implied that the benchmark uses a JavaScript engine or runtime environment to execute the tests. The JavaScript engine's behavior and performance characteristics can affect the results of this benchmark.

**Special JS Features/Syntax**

The spread operator (`...`) is a modern JavaScript feature introduced in ES6 (ECMAScript 2015). It allows for spreading the elements of an array into a new array, making it easier to concatenate arrays or create new arrays with specific values.

**Other Alternatives**

If not using the Array.prototype.concat() method, other alternatives for concatenating arrays include:

1. **Array.prototype.push()**: Adding elements one by one to the end of an array.
2. **Array.prototype.unshift()**: Adding elements to the beginning of an array.
3. **Slice() + Concat()**: Using `slice()` to create a new array with specific values and then concatenating it with another array using `concat()`.

However, these alternatives are generally less efficient than the spread operator (`...`) for small arrays.

**Benchmark Considerations**

The benchmark provides valuable insights into the performance differences between various approaches to concatenate arrays in JavaScript. When choosing an approach, consider factors such as:

1. **Performance**: For large arrays, using a manual loop or the spread operator might be faster.
2. **Readability and maintainability**: For most cases, the spread operator (`...`) is a clear winner due to its readability and simplicity.
3. **Browser support**: If targeting older browsers (e.g., IE 11), consider using the Array.prototype.concat() method.

Keep in mind that this benchmark only compares three specific approaches and does not account for all possible scenarios or edge cases.

Related benchmarks:

Array concat vs spread operator vs loop push (version: 0)

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

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

Created: 5 years ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

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):