Benchmark: Array.prototype.concat vs spread operatordfg

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: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36

Browser/OS: Chrome 83 on Windows

View result in a separate tab

Test name	Executions per second
Array.prototype.concat	3948893.8 Ops/sec
spread operator	18030740.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Overview**

The benchmark, named "Array.prototype.concat vs spread operator", compares two ways to merge arrays in JavaScript: the traditional `concat()` method and the new ES6 spread operator (`...`).

**Test Cases**

There are two test cases:

1. **Array.prototype.concat**
This test case uses the traditional `concat()` method to merge an array of strings, a boolean value, and an integer.

```javascript
var params = [ "hello", true, 7 ];
var other = [ 1, 2 ].concat(params);
```

2. **Spread Operator**
This test case uses the new ES6 spread operator (`...`) to merge an array of strings, a boolean value, and an integer into another array.

```javascript
var params = [ "hello", true, 7 ];
var other = [ 1, 2, ...params ];
```

**Library Used**

In both test cases, no specific library is used. The `concat()` method is part of the built-in JavaScript Array prototype, while the spread operator (`...`) was introduced in ECMAScript 2015 (ES6).

**Special JS Feature/Syntax**

The spread operator (`...`) is a new feature introduced in ES6, which allows for more concise array merging. It's also known as the "rest parameter" syntax.

**Pros and Cons of Approaches**

**Traditional `concat()` Method:**

Pros:

* Widely supported across older browsers
* Easy to implement

Cons:

* Less readable due to its verbose nature
* Can lead to unnecessary allocations (e.g., creating intermediate arrays)

**Spread Operator (`...`):**

Pros:

* More concise and readable syntax
* Avoids unnecessary allocations, as it directly merges arrays in memory

Cons:

* Requires support for ES6+ browsers or transpilation/compilation
* May not work correctly in older browsers that don't understand the spread operator

**Other Alternatives**

In modern JavaScript development, other methods like `Array.prototype.push()` and using `Array.from()` might also be used for array merging. However, these approaches have slightly different performance characteristics compared to `concat()` and the spread operator.

For example:

* `push()` can lead to more efficient updates in some cases, but it may not work correctly if you're trying to merge multiple arrays.
* `Array.from()` creates a new array from an iterable (like an array of strings), which might be less efficient than using the spread operator or `concat()`.

Related benchmarks:

Array.prototype.concat vs spread operatordfg (version: 0)

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

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

Created: 4 years 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 one month ago):