Benchmark: ci - spread vs push

Script Preparation code:

function getRandomInt(max) {
    return Math.floor(Math.random() * max);
}

function createItem(type, i) {
    return (type === "buzz") ? {
        type: "buzz",
        m: Math.random(),
        s: Math.random()
    } : {
        type: type,
        subvals: {
            a: Math.random(),
            b: Math.random(),
            c: Math.random(),
            d: Math.random(),
        }
    }

}
var baseItems = [];
for (let i = 0; i < 100; i++) {
    const type = i % 3 === 0 ? "fizz" : i % 5 === 0 ? "buzz" : "whatever";
    baseItems.push(createItem(type, i));
}

Tests:

spread
var spreadItems = baseItems.reduce((acc, current) => { if(current.type === "buzz") { acc.buzz = [...acc.buzz, { a: current.m }] } else { acc.fizzyWhatevs = [...acc.fizzyWhatevs,{ a: current.subvals.a }] } return acc; }, { fizzyWhatevs: [], buzz: [] })
push
var pushItems = baseItems.reduce((acc, current) => { if(current.type === "buzz") { acc.buzz.push({ a: current.m }) } else { acc.fizzyWhatevs.push({ a: current.subvals.a }) } return acc; }, { fizzyWhatevs: [], buzz: [] })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
push

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark is comparing two approaches to manipulate an array of objects: `Array.prototype.push()` versus using `Array.prototype.reduce()` with object spreading (`...`).

**Test Cases**

There are two test cases:

1. `push`: This test case uses the traditional `push()` method to add elements to the `fizzyWhatevs` and `buzz` arrays.
2. `spread`: This test case uses the spread operator (`...`) to create a new array and add elements to it, which is then used as the value of the `fizzyWhatevs` or `buzz` property in the accumulator object.

**Library**

In both test cases, the `Array.prototype.reduce()` method is used, but no specific library is required. However, if we consider the spread operator (`...`) introduced in ECMAScript 2018 (ES2020), it's worth noting that older browsers may not support it.

**Special JS Feature/Syntax**

The benchmark uses a feature that was introduced in ECMAScript 2019 (ES2020): the optional chaining operator (`?.`) is not used, but the spread operator (`...`) is. However, there's no special syntax or feature being tested in this benchmark.

**Options Compared**

Two options are compared:

1. **`Array.prototype.push()`**: This traditional approach uses the `push()` method to add elements to an array.
2. **Spread Operator (`...`)**: This modern approach uses object spreading to create a new array and add elements to it.

**Pros and Cons of Each Approach**

Here's a brief summary of the pros and cons of each approach:

**`Array.prototype.push()`**

Pros:

* Widely supported across all browsers
* Fast and efficient
* Well-established API

Cons:

* Can lead to performance issues when working with large datasets due to frequent array resizing

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

Pros:

* Modern and efficient for creating new arrays
* Reduces memory allocation and copying of elements
* Better suited for large datasets

Cons:

* Requires ECMAScript 2018 (ES2020) support in older browsers
* Can be slower than traditional `push()` due to the overhead of object creation

**Other Considerations**

When choosing between these two approaches, consider the following factors:

* **Browser Support**: If you need to support older browsers, use the traditional `push()` method.
* **Performance**: For large datasets, the spread operator (`...`) is generally faster and more efficient.
* **Readability**: Use the spread operator (`...`)) when creating new arrays to improve code readability.

**Alternatives**

Other alternatives for array manipulation include:

1. `Array.prototype.map()`: Transforms an array by applying a function to each element, returning a new array.
2. `Array.prototype.filter()`: Creates a new array with all elements that pass the test implemented by a provided function.
3. `Array.prototype.slice()`: Returns a shallow copy of a portion of an array.

In this benchmark, neither of these alternatives is used.

Related benchmarks:

ci - spread vs push (version: 0)

Comparing performance of: spread vs push

Created: 3 years ago by: Guest

Jump to the latest result

spread

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):