Benchmark: Test Loop Set Data

Script Preparation code:

var arr = new Array(15000);
arr.fill({ id: 0, text: "test" });
arr = arr.map((el, idx) => el.id = idx);
var foo = Math.floor(Math.random() * 15000);

Tests:

1
const index = arr.findIndex((itm) => itm.id === foo); const newArr = [...arr]; arr[index] = {...arr[index], text: "edittest"}
2
const newArr = arr.map((row, index) => { if (index === 1) { return { ...row, text: "edittest" } } })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
1
2

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36

Browser/OS: Chrome 125 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
1	1144.0 Ops/sec
2	14992.5 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the provided benchmark.

**What is being tested?**

The provided benchmark tests two different approaches to updating an array of objects in JavaScript:

1. Using `Array.prototype.findIndex()` and then using destructuring assignment (`arr[index] = {...arr[index], text: "edittest"}`)
2. Using `Array.prototype.map()` with a custom callback function that checks the index and updates the corresponding object

**Options being compared**

The two options are:

* Option 1: `findIndex` + destructuring assignment
* Option 2: `map()` with a custom callback function

**Pros and Cons of each approach**

Option 1: `findIndex` + destructuring assignment

Pros:

* More efficient, as it only searches for the index once and then updates the value at that index.
* Less memory overhead, as it doesn't create a new array.

Cons:

* May be slower due to the additional step of finding the index before updating the value.
* Requires careful handling of edge cases (e.g., what if the element is not found in the array?)

Option 2: `map()` with custom callback function

Pros:

* Easier to read and understand, as it clearly conveys the intent of updating a specific element.
* Can be more flexible, as the callback function can perform additional operations.

Cons:

* Less efficient, as it creates a new array with updated elements.
* May consume more memory if the original array is large.

**Library usage**

In both test cases, no libraries are explicitly mentioned. However, `Array.prototype.findIndex()` and `Array.prototype.map()` are part of the built-in JavaScript API, so no additional libraries are required.

**Special JS features or syntax**

There are two special features used in this benchmark:

* **Destructuring assignment**: Used in Option 1 to update the value at a specific index. Destructuring assignment is a feature introduced in ECMAScript 2015 (ES6) that allows assigning properties of an object to variables.
* **Template literals**: Used in Option 2's `map()` callback function to create a new object with updated properties. Template literals are a feature introduced in ECMAScript 2015 (ES6) that allows creating string literals with expressions.

**Other alternatives**

If you wanted to compare other approaches, some alternatives could be:

* Using `Array.prototype.forEach()` with an index variable
* Using a custom loop or for-each iteration to update the array elements
* Using a library like Lodash's `map` function

However, these alternatives are likely to introduce more overhead and complexity compared to the two options being tested.

Related benchmarks:

Test Loop Set Data (version: 0)

Comparing performance of: 1 vs 2

Created: one year ago by: Guest

Jump to the latest result

1

2

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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