Benchmark: Array concat vs spread operator vs push single item

Tests:

Array.prototype.concat
var params = [ "hello", true, 7 ]; var other = params.concat(1);
spread operator
var params = [ "hello", true, 7 ] var other = [ ...params, 1 ]
Push
var params = [ "hello", true, 7 ]; var other = params.push(1);

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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**Benchmark Explanation**

The provided benchmark measures the performance of three different approaches to concatenate an array in JavaScript: the traditional `concat()` method, the new ES6 spread operator (`...`), and the `push` method.

**Options Compared**

1. **Array.prototype.concat**: This method creates a new array by concatenating the elements of the original array with the specified elements.
2. **Spread Operator (new ES6 syntax)**: This operator creates a new array from an existing array and additional elements, effectively creating a shallow copy of the original array.
3. **Push Method**: This method adds one or more elements to the end of an array.

**Pros and Cons**

* **Array.prototype.concat**:
	+ Pros: well-established, widely supported, easy to understand.
	+ Cons: creates a new array, which can lead to performance issues for large datasets.
* **Spread Operator (new ES6 syntax)**:
	+ Pros: concise, efficient, creates a shallow copy of the original array.
	+ Cons: relatively new syntax, may not be well-supported in older browsers or environments.
* **Push Method**:
	+ Pros: easy to understand, fast, and efficient for small datasets.
	+ Cons: modifies the original array, which can lead to unexpected behavior if used incorrectly.

**Library Used**

There is no library explicitly mentioned in the provided benchmark definitions. However, it's worth noting that some JavaScript engines or environments might have built-in optimizations or libraries that affect the performance of these methods.

**Special JS Feature/Syntax**

The spread operator (`...`) is a relatively new feature introduced in ES6 (ECMAScript 2015). It allows creating a new array from an existing array and additional elements. This syntax is concise and efficient but might not be supported by older browsers or environments.

**Other Alternatives**

If you're looking for alternative approaches to concatenate arrays, here are a few more options:

1. **Array.prototype.slice()**: Creates a shallow copy of the original array.
2. **Array.prototype.reduce()**: Can be used to concatenate arrays by reducing an accumulator with the elements of the array.
3. **String concatenation**: For small datasets, concatenating strings using the `+` operator can be faster than creating an array and using one of the above methods.

Keep in mind that the performance differences between these alternatives may not be significant for small datasets or simple use cases, but they might become important as the dataset size increases or when working with large amounts of data.

Related benchmarks:

Array concat vs spread operator vs push single item (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):