Benchmark: fromEntries vs reduce 2

Tests:

fromEntries
const myValues = []; for (let i = 0; i < 10000; i++) { myValues.push({ key: `key${i}`, value: `value${i}` }) } const myObject = Object.fromEntries(myValues.map(({ key, value }) => [key, value]));
reduce
const myValues = []; for (let i = 0; i < 10000; i++) { myValues.push({ key: `key${i}`, value: `value${i}` }) } const myObject = myValues.reduce((acc, {key, value}) => { acc[key] = value; return acc; });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
fromEntries
reduce

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 definition and individual test cases to understand what is being tested.

**Benchmark Definition:**
The provided JSON represents a JavaScript microbenchmark, where users can create and run benchmarks on their own code. The benchmark definition is an empty object with the following properties:

* "Name": "fromEntries vs reduce 2" - This is the name of the benchmark.
* "Description": null - There is no description for this benchmark.
* "Script Preparation Code": null - There is no script preparation code provided.
* "Html Preparation Code": null - There is no HTML preparation code provided.

**Individual Test Cases:**
The benchmark definition contains two individual test cases:

1. `fromEntries`:
	* Benchmark Definition: This code creates an array of objects, pushes each object onto the array, maps over the array to create a new array of key-value pairs, and then uses `Object.fromEntries()` to create a new object from the array.
2. `reduce`:
	* Benchmark Definition: This code creates an array of objects, pushes each object onto the array, maps over the array to create a new array of key-value pairs, and then uses the `reduce()` method to iterate over the array and create a new object.

**What is being tested?**
The benchmark is testing two approaches for creating an object from an array of key-value pairs:

1. Using `Object.fromEntries()`: This approach creates a new object by passing an array of key-value pairs to `Object.fromEntries()`.
2. Using the `reduce()` method: This approach iterates over the array and assigns each value to the corresponding key in an accumulator object.

**Options compared:**
The benchmark is comparing two options for creating an object from an array of key-value pairs:

1. `Object.fromEntries()`: A built-in JavaScript method that creates a new object by passing an array of key-value pairs.
2. The `reduce()` method: A built-in JavaScript method that iterates over the array and assigns each value to the corresponding key in an accumulator object.

**Pros and Cons:**

* **`Object.fromEntries()`**:
	+ Pros:
		- Concise and expressive syntax
		- Efficient and optimized implementation
	+ Cons:
		- Requires modern browsers (Chrome 111 and above)
		- May not be supported in older browsers or environments
* **The `reduce()` method**:
	+ Pros:
		- Wide support across different browsers and environments
		- Can be used for more complex transformations beyond just key-value pairs
	+ Cons:
		- Less concise syntax than `Object.fromEntries()`
		- Requires manual management of the accumulator object

**Library usage:**
None of the benchmark code uses any external libraries or dependencies.

**Special JS feature/syntax:**
No special JavaScript features or syntax are used in these benchmark codes. The `reduce()` method is a built-in JavaScript method that requires no additional setup or configuration.

**Other alternatives:**
If you want to create an object from an array of key-value pairs without using the `Object.fromEntries()` method, you can also use other approaches such as:

* Using the spread operator (`{ ... }`) and iterating over the array
* Using a library like Lodash's `fromPairs` function
* Writing your own custom implementation using a loop or recursive function

Related benchmarks:

fromEntries vs reduce 2 (version: 0)

Comparing performance of: fromEntries vs reduce

Created: 3 years ago by: Guest

Jump to the latest result

fromEntries

reduce

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):