Benchmark: Spread vs object assign array of objects 2

Tests:

Obj assign
const a = { Color: 'red', Font: 'big' }; const colA = [ { Name: 'cola' }, { Name: 'colb' } ]; colA.forEach(item => { Object.assign(item, a); });
For for
const a = { Color: 'red', Font: 'big' }; const colA = [ { Name: 'cola' }, { Name: 'colb' } ]; for (let i = 0; i < colA.length; i++) { const item = colA[i]; for (const key in a) { item[key] = a[key]; } }
For for 2
const a = { Color: 'red', Font: 'big' }; const colA = [ { Name: 'cola' }, { Name: 'colb' } ]; for (const item of colA) { for (const key in a) { item[key] = a[key]; } }
Spread
const a = { Color: 'red', Font: 'big' }; const colA = [ { Name: 'cola', ...a }, { Name: 'colb', ...a } ];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Obj assign
For for
For for 2
Spread

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 benchmark and its components.

**Benchmark Definition**

The benchmark is defined by a JSON object with four properties: `Name`, `Description`, `Script Preparation Code`, and `Html Preparation Code`. In this case, all properties are empty or null, indicating that no additional setup or preparation code is required.

**Individual Test Cases**

There are four test cases in the benchmark, each with its own definition in the `Benchmark Definition` property. These definitions specify how to create an array of objects and perform some operations on it.

1. **Test Case 1: "Obj assign"**
	* The script creates an object `a` with properties `Color` and `Font`, and an array `colA` containing two objects.
	* It then loops through each item in the array using `forEach`, and for each item, it uses `Object.assign()` to copy the properties of `a` into the item.
2. **Test Case 2: "For for"**
	* Similar to Test Case 1, but instead of using `forEach`, it uses a traditional `for` loop to iterate through the array and apply the same property copying operation to each item.
3. **Test Case 3: "For for 2"**
	* Again, similar to Test Case 2, but with an additional twist: it uses the new `for...of` loop syntax to iterate through the array and copy properties from `a`.
4. **Test Case 4: "Spread "**
	* The script creates an object `a` with properties `Color` and `Font`, and an array `colA` containing two objects.
	* It then uses the spread operator (`...`) to create a new array where each item is a copy of the original object, using this syntax.

**Library and Special JavaScript Features**

None of the test cases use any external libraries or custom JavaScript features. However, it's worth noting that the `for...of` loop syntax used in Test Case 3 was introduced in ECMAScript 2015 (ES6) and has since become a standard feature in modern browsers.

**Options Compared**

The benchmark is comparing four different approaches to iterate through an array and copy properties from one object into each item:

1. `forEach`
2. Traditional `for` loop
3. New `for...of` loop syntax

Each approach has its pros and cons:

* **`forEach`**: Easy to read, concise, and widely supported. However, it may be slightly slower than traditional loops due to the overhead of the method call.
* **Traditional `for` loop**: More control over iteration, but can be verbose and harder to read for complex iterations.
* **New `for...of` loop syntax**: Concise, modern, and efficient. However, it's a relatively new feature that may not be supported in older browsers.

**Other Considerations**

When comparing these approaches, consider factors such as:

* Performance: How does each approach perform in terms of CPU cycles and memory usage?
* Readability: Which approach is easier to understand and maintain for other developers?
* Browser Support: Are there any differences in behavior or support between modern browsers?

In this case, the benchmark results suggest that the new `for...of` loop syntax is the fastest approach, followed closely by traditional loops. The `forEach` method is slower, likely due to the overhead of the method call.

**Alternatives**

If you're looking for alternatives to these approaches, consider:

* Using a library like Lodash or Ramda to provide a more concise and expressive way of iterating over arrays.
* Exploring other iteration methods, such as `map`, `filter`, or `reduce`.
* Implementing custom iterations using low-level browser APIs, if necessary.

Related benchmarks:

Spread vs object assign array of objects 2 (version: 0)

Comparing performance of: Obj assign vs For for vs For for 2 vs Spread

Created: 2 years ago by: Guest

Jump to the latest result

Obj assign

For for

For for 2

Spread

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):