Benchmark: Object Array update prop1

Script Preparation code:

var array = (new Array(100)).fill(0).map((x, i) => {
    return {
        value: i + 1,
        name: `name ${i+1}`,
        nameDealer: `nameDealer ${i+1}`
    }
})

Tests:

For in
for (let accessory of array) { console.log(accessory); if (accessory.nameDealer) { accessory.name = accessory.nameDealer; } }
For each
array.forEach((item) => { console.log(item); if (item.nameDealer) { item.name = item.nameDealer; } })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
For in
For each

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark and explain the options compared, their pros and cons, and other considerations.

**What is being tested?**

The benchmark tests two ways to update property values in an array of objects: using `for...in` loops (specifically, `for...of`) and using `forEach()`. The test case aims to measure which approach is faster for a large array of 100 objects.

**Options compared**

1. **For-in loop**: This method iterates over the properties of an object in the array, including inherited ones. The property names are not guaranteed to be in a predictable order.
2. **For...of loop**: This method iterates over the elements of an array and provides access to the array's elements as individual objects (in this case, objects with `value`, `name`, and `nameDealer` properties).
3. **forEach()**: This is a built-in JavaScript method that iterates over the elements of an array and calls a provided function once for each element.

**Pros and Cons**

1. **For-in loop**:
	* Pros: Can be used with any object, not just arrays.
	* Cons: Iterates over all properties (including inherited ones), which can lead to slower performance due to additional iterations.
2. **For...of loop**:
	* Pros: Only iterates over the array's elements, providing direct access to each element as an individual object.
	* Cons: May not be suitable for objects with a large number of properties or complex inheritance hierarchies.
3. **forEach()**:
	* Pros: Simple and efficient, only iterating over the array's elements.
	* Cons: Does not provide direct access to each element's properties; instead, it requires accessing them through the function provided.

**Other considerations**

* The `nameDealer` property is used as a fallback for updating the `name` property. This might be done to avoid issues with property existence or nullability.
* The test case uses a large array of 100 objects, which can amplify performance differences between the three approaches.

**Library and special JavaScript features**

There are no specific libraries mentioned in the benchmark definition. However, it's worth noting that `forEach()` is a built-in JavaScript method, making it a native option.

**Special JavaScript feature**

The test case uses a feature called "template literals" (`\r\nreturn {\r\n...},\r\n`) to create an array of objects with dynamic property names. This feature was introduced in ECMAScript 2015 (ES6).

**Alternatives**

Other alternatives for iterating over arrays and updating object properties could include:

1. Using `map()` or `reduce()` methods, which provide more functional programming-like APIs.
2. Using a traditional `for` loop with an index variable to access each element directly.
3. Using libraries like Lodash (which provides various utility functions for array operations).
4. Using specialized libraries like Ramda (which provides functional programming utilities).

Keep in mind that the choice of iteration method ultimately depends on the specific use case and performance requirements.

Related benchmarks:

Object Array update prop1 (version: 1)

Test update 1 value of each of the objects in a n array

Comparing performance of: For in vs For each

Created: 2 years ago by: Registered User

Jump to the latest result

For in

For each

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):