Benchmark: foreach vs map in resizeobs

HTML Preparation code:

<div class="box"></div>
<div class="box"></div>
<div class="box"></div>

Script Preparation code:

const ro = new ResizeObserver((entries) => {
      const childHeightArray = [];
      entries.forEach((entry) => {
        return childHeightArray.push(entry.contentRect.height);
      });

      console.log(childHeightArray);
    });
    document.querySelectorAll('.box')

Tests:

map
const ro = new ResizeObserver((entries) => { const childHeightArray = []; entries.forEach((entry) => { return childHeightArray.push(entry.contentRect.height); }); console.log(childHeightArray); }); document.querySelectorAll('.box')
foreach
const ro = new ResizeObserver((entries) => { const childHeightArray = []; entries.map((entry) => { return childHeightArray.push(entry.contentRect.height); }); console.log(childHeightArray); }); document.querySelectorAll('.box')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
map
foreach

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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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 the provided benchmark and its test cases.

**Benchmark Description**

The benchmark compares two approaches to iterate over an array of entries returned by the `ResizeObserver` API: using a traditional `forEach` loop (test case "foreach") versus using the `map` method (test case "map").

**Test Cases Comparison**

In both test cases, we have:

1. A script preparation code that:
	* Creates a new instance of `ResizeObserver`.
	* Defines a callback function that will be executed when the observed elements are resized.
	* Within this callback function, an array (`childHeightArray`) is created to store the heights of the child elements.
2. An HTML preparation code that creates three identical `<div>` elements with class "box".
3. The `forEach` or `map` method is applied to the array of entries returned by the `ResizeObserver`. This will iterate over each entry and push its `contentRect.height` value into the `childHeightArray`.
4. After iterating over all entries, the `console.log` statement outputs the contents of the `childHeightArray`.

**Options Compared**

The two options being compared are:

1. **forEach loop**: Iterates over each element in the array using a traditional `for` loop.
2. **map method**: Creates a new array by applying a transformation function to each element in the original array.

**Pros and Cons of Each Approach**

* **forEach Loop (Traditional Iteration)**:
	+ Pros: Easy to understand, can be used for simple iterations.
	+ Cons: Less efficient than map for large datasets, can lead to slower performance due to unnecessary array creation.
* **Map Method (Transformed Array)**:
	+ Pros: More concise and expressive, less overhead than traditional iteration, can improve performance by reducing unnecessary array creation.
	+ Cons: May be less intuitive for developers unfamiliar with the map method.

**Libraries Used**

None are explicitly mentioned in this benchmark. However, it's worth noting that `ResizeObserver` is a part of the Web APIs and doesn't rely on any external libraries.

**Special JavaScript Features/Syntax (None)**

No special JavaScript features or syntax are used in these test cases.

**Other Considerations**

* The `ResizeObserver` API is relatively new and still evolving. As such, its performance and behavior may change over time.
* The benchmark's results can be influenced by factors such as the browser, operating system, device platform, and hardware configuration.

**Alternatives**

If you wanted to run similar benchmarks for other iteration methods, some alternatives could include:

* Using `for...of` loop (ECMAScript 2015+): Similar to `forEach`, but with a more concise syntax.
* Using `reduce()` method: A different approach that can be used to iterate over an array and accumulate values.

Keep in mind that the best iteration method for your specific use case will depend on factors such as performance requirements, code readability, and personal preference.

Related benchmarks:

foreach vs map in resizeobs (version: 0)

Comparing performance of: map vs foreach

Created: 5 years ago by: Guest

Jump to the latest result

map

foreach

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):