Benchmark: Array concat vs spread operator vs push #4

Tests:

spread operator
var other = [ 1, 2 ] var other2 = [...other, 3] var other3 = [...other2, 4] var other4 = [...other3, 5] var other5 = [...other4, 6] var other6 = [...other5, 7]
Push
var other = [ 1, 2 ]; other.push(3); other.push(4); other.push(5); other.push(6); other.push(7);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread operator
Push

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.36

Browser/OS: Chrome 146 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
spread operator	10002305.0 Ops/sec
Push	66440372.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and the pros and cons of each approach.

**Benchmark Overview**

The benchmark compares three methods to concatenate an array:

1. **Push**: Using the `push()` method to add elements to the end of an array.
2. **Spread Operator (`...`)**: Using the new ES6 spread operator to create a new array with elements from another array.
3. **Concat** (not explicitly used in the provided benchmark, but mentioned in the initial benchmark definition): Using the `concat()` method to concatenate arrays.

**Options Compared**

The two main options being compared are:

1. **Push**: Adding elements to an existing array using the `push()` method.
2. **Spread Operator (`...`)**: Creating a new array with elements from another array using the spread operator.

**Pros and Cons of Each Approach:**

### Push

Pros:

* Efficient for small arrays, as it only requires updating the internal array buffer.
* Can be faster than creating a new array due to cache locality.

Cons:

* Creates a new internal array buffer each time an element is added, which can lead to memory fragmentation and garbage collection overhead for large arrays.
* Not suitable for large datasets, as it can cause performance issues.

### Spread Operator (`...`)

Pros:

* Creates a new array with elements from another array, which can be more efficient than using `push()` for large datasets.
* Allows for easier creation of arrays with multiple sources (e.g., `var arr = [1, 2, ...arr]`).

Cons:

* Can be slower than `push()` due to the overhead of creating a new array and copying elements.
* May not perform as well on small arrays or when dealing with sparse arrays.

**Library and Special JS Feature:**

There is no explicit library mentioned in the provided benchmark. However, the use of the spread operator (`...`) is a feature introduced in ES6 (ECMAScript 2015).

**Other Considerations:**

* Cache locality: Both `push()` and the spread operator can benefit from cache locality, as they modify the internal array buffer.
* Garbage collection overhead: Creating a new internal array buffer using `push()` can lead to increased garbage collection overhead for large arrays.

**Alternative Approaches:**

1. **Concat**: Using the `concat()` method would have been an alternative approach, but it's not explicitly used in this benchmark.
2. **Array methods like `unshift()` or `splice()`: These methods can also be used to concatenate arrays, but their performance may vary depending on the specific use case.
3. **Other libraries or frameworks**: Depending on the specific requirements of the project, other libraries or frameworks might provide optimized implementations for array concatenation.

In summary, the benchmark compares two approaches: `push()` and the spread operator (`...`). The choice between these two depends on the specific use case and performance requirements. While `push()` is efficient for small arrays, the spread operator can be more suitable for large datasets due to its ability to create a new array with elements from another array.

Related benchmarks:

Array concat vs spread operator vs push #4 (version: 0)

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

Comparing performance of: spread operator vs Push

Created: 5 years ago by: Guest

Jump to the latest result

spread operator

Push

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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