Benchmark: Array.prototype.concat vs spread operator simple

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 ]

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

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36

Browser/OS: Chrome 108 on Windows

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Test name	Executions per second
Array.prototype.concat	9254216.0 Ops/sec
spread operator	39096440.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and provide insights on the test cases.

**Benchmark Overview**

The MeasureThat.net website provides a platform for creating and running JavaScript microbenchmarks. The benchmark in question compares two approaches to merge arrays: the traditional `Array.prototype.concat()` method and the new ES6 spread operator (`...`).

**Options Compared**

Two options are compared:

1. **Traditional `Array.prototype.concat()`**: This is an older method for merging arrays, which was widely used before the introduction of the spread operator.
2. **ES6 Spread Operator (`...`)**: Introduced in ECMAScript 2015 (ES6), this operator allows for more concise and expressive way to merge arrays.

**Pros and Cons**

* **Traditional `Array.prototype.concat()`**: Pros:
	+ Wide support across older browsers and Node.js versions.
	+ Clear and simple syntax.
*	Cons:
	+ Less concise than the spread operator.
	+ Can lead to performance issues for large datasets due to the creation of a new array object.
* **ES6 Spread Operator (`...`)**: Pros:
	+ More concise and readable syntax.
	+ Creates a shallow copy of the original array, avoiding unnecessary re-allocations.
	+ Better performance than `concat()` for large datasets.

However, the spread operator also has some cons:

* Less supported across older browsers and Node.js versions (although it's widely adopted).
* May lead to issues with array references and prototype chain inheritance.

**Library and Special JS Features**

In this benchmark, there is no explicit library mentioned. However, the test cases assume that the `Array` object and its methods are available in the testing environment.

There are no special JavaScript features mentioned in the benchmark definition or individual test cases.

**Other Considerations**

When choosing between `concat()` and the spread operator, consider the following factors:

* Code readability: If you prefer a more concise syntax, use the spread operator.
* Performance: For large datasets, use the spread operator for better performance.
* Browser compatibility: If you need to support older browsers or versions, use `concat()`.
* Array references and prototype chain inheritance: Be cautious when using the spread operator, as it may lead to issues with these aspects.

**Alternatives**

Other alternatives for merging arrays include:

* Using `Array.prototype.push.apply()` (less common and less efficient than `concat()`).
* Creating a new array object using the `Array` constructor and pushing elements from both arrays (more verbose but more control).

However, in most cases, `concat()` and the spread operator are sufficient and widely supported.

Related benchmarks:

Array.prototype.concat vs spread operator simple (version: 0)

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

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

Created: one year ago by: Guest

Jump to the latest result

Array.prototype.concat

spread operator

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):