Benchmark: Array.prototype.concat vs spread operator 1

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 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.121 Safari/537.36

Browser/OS: Chrome 85 on Linux

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Test name	Executions per second
Array.prototype.concat	5471978.0 Ops/sec
spread operator	22789494.0 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 benchmark and explain what's being tested.

**Overview**

The benchmark compares two approaches to merge arrays in JavaScript: using the `concat()` method (a traditional approach) versus the new ES6 spread operator (`...`).

**Options Compared**

Two options are compared:

1. **Array.prototype.concat()**: A traditional way to concatenate arrays in JavaScript.
2. **Spread Operator (`...`)**: A new, concise way to merge arrays introduced in ES6.

**Pros and Cons of Each Approach**

* **Array.prototype.concat()**:
	+ Pros:
		- Well-established, widely supported, and well-documented.
		- Can handle any type of object as the first argument (not just arrays).
	+ Cons:
		- Less concise than the spread operator.
		- May have performance implications due to creating a new array object.
* **Spread Operator (`...`)**:
	+ Pros:
		- Concise and readable syntax.
		- Only creates a shallow copy of the source array, which can be more efficient for large arrays.
		- Supports merging multiple arrays using `...`
	+ Cons:
		- May not work as expected with certain data types or array structures (e.g., non-array objects).
		- May require careful consideration when working with null or undefined values.

**Library Used**

None. This benchmark only uses built-in JavaScript features.

**Special JS Feature/Syntax**

The spread operator (`...`) is a new feature introduced in ES6, which allows concise array merging.

**Other Considerations**

* Performance: The benchmark measures the execution speed of both approaches.
* Memory usage: Although not explicitly measured, the spread operator may be more memory-efficient due to its shallow copy nature.
* Readability and maintainability: The concise syntax of the spread operator can improve code readability, but it may also make debugging more challenging.

**Alternative Approaches**

Other ways to merge arrays in JavaScript include:

1. Using `Array.prototype.push()`: A more traditional approach that appends elements to an array by using `push()` method.
2. Using `Array.prototype.splice()`: An alternative approach that modifies the original array by removing and inserting elements at specific positions.
3. Using a library or utility function: There are libraries, such as Lodash, or utility functions, like `mergeArrays()`, that provide a more concise way to merge arrays.

Keep in mind that these alternatives may have different performance characteristics, readability implications, and trade-offs compared to the spread operator and traditional `concat()` method.

Related benchmarks:

Array.prototype.concat vs spread operator 1 (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):