Benchmark: Object.fromEntries vs reduce test 4

Script Preparation code:

var data = { ...Array.from(Array(10000).keys()) };

Tests:

Object.fromEntries
Object.fromEntries(Object.entries(data).map((key, value) => [!value ? `invalid-${key}` : key, value]));
Reduce (reuse object)
Object.entries(data).reduce((acc, [k, v]) => { acc[!v ? `invalid-${k}` : k] = v; return acc; }, {});
Reduce (creating temporary objects)
Object.entries(data).reduce((acc, [k, v]) => ({ ...acc, [!v ? `invalid-${k}` : k]: v }), {});

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.fromEntries
Reduce (reuse object)
Reduce (creating temporary objects)

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/116.0.0.0 Safari/537.36

Browser/OS: Chrome 116 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.fromEntries	180.8 Ops/sec
Reduce (reuse object)	1635.6 Ops/sec
Reduce (creating temporary objects)	0.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark measures the performance of three different approaches to create an object from a list of key-value pairs:

1. `Object.fromEntries`
2. Using `reduce` with reusing an existing object (`Reduce (reuse object)`)
3. Using `reduce` without creating temporary objects (`Reduce (creating temporary objects)`)

**Options being compared**

The three options are:

* `Object.fromEntries`: a built-in JavaScript method that creates an object from an array of key-value pairs.
* `Reduce (reuse object)`: uses the `reduce` method to create a new object by iteratively appending key-value pairs to an existing object.
* `Reduce (creating temporary objects)`: similar to the previous option, but creates a new object for each iteration, resulting in more memory allocations.

**Pros and Cons**

1. **Object.fromEntries**:
	* Pros: efficient, concise, and easy to read.
	* Cons: may not be supported by older browsers or JavaScript engines.
2. **Reduce (reuse object)**:
	* Pros: can avoid unnecessary object creations, reducing memory allocation overhead.
	* Cons: requires more complex code, and the reuse of objects might lead to unexpected behavior if not used carefully.
3. **Reduce (creating temporary objects)**:
	* Pros: easier to understand for developers familiar with `reduce`, as it uses a more traditional approach.
	* Cons: results in unnecessary object creations, which can impact performance.

**Library usage**

None of the benchmark options explicitly use any external libraries.

**Special JS features or syntax**

The benchmark does not utilize any special JavaScript features or syntax that require specific handling (e.g., async/await, Promises, etc.).

**Other alternatives**

Alternative approaches to create an object from a list of key-value pairs could include:

* Using `Array.prototype.reduce()` directly on the array, without creating an intermediate object.
* Utilizing libraries like Lodash or Underscore.js, which provide optimized implementations for this common use case.

However, these alternative approaches are not explicitly tested in the provided benchmark.

Related benchmarks:

Object.fromEntries vs reduce test 4 (version: 0)

Comparing performance of: Object.fromEntries vs Reduce (reuse object) vs Reduce (creating temporary objects)

Created: one year ago by: Guest

Jump to the latest result

Object.fromEntries

Reduce (reuse object)

Reduce (creating temporary objects)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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