Benchmark: Reduce Object vs Map

Script Preparation code:

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

Tests:

Reusing object
Object.entries(data).reduce((acc, [k, v]) => { acc[k] = v.toString(); return acc; }, {});
Creating new object
Object.entries(data).reduce((acc, [k, v]) => ({ ...acc, [k]: v.toString() }), {});
Using map
Object.entries(data).reduce((acc, [k, v]) => { acc.set(k,v) return acc; }, new Map());

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Reusing object
Creating new object
Using map

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**What is being tested?**

MeasureThat.net is testing three different approaches to iterating over an array and reducing an object in JavaScript:

1. **Reusing object**: This approach uses the `reduce` method on the original object, modifying its properties directly.
2. **Creating new object**: This approach creates a new object and adds properties to it using the `reduce` method.
3. **Using map**: This approach uses the `Map` data structure to iterate over the array and accumulate values.

**Options compared**

The benchmark is comparing these three approaches in terms of execution time, with the goal of determining which one is the fastest.

**Pros and cons of each approach:**

1. **Reusing object**:
	* Pros: Modifies the original object, potentially reducing memory allocation and copying.
	* Cons: Can lead to unexpected behavior if not used carefully (e.g., modifying properties that are not intended to be modified).
2. **Creating new object**:
	* Pros: Creates a new object with isolated properties, which can prevent side effects.
	* Cons: Requires more memory allocation and copying than reusing the original object.
3. **Using map**:
	* Pros: Provides a clear and explicit way to iterate over an array and accumulate values in a separate data structure.
	* Cons: May have higher overhead due to the creation of a new `Map` object.

**Library used**

In the benchmark code, no libraries are explicitly mentioned, but the use of `Array.from()` suggests that the test is using the built-in `Array` and `String` functions from JavaScript.

**Special JS feature/syntax**

The benchmark does not appear to use any special JavaScript features or syntax beyond what is required for the comparisons. However, it's worth noting that the use of `reduce` and `Map` implies some familiarity with functional programming concepts in JavaScript.

**Other alternatives**

In addition to these three approaches, other possible ways to iterate over an array and reduce an object might include:

* Using a `for...of` loop or a traditional `for` loop
* Utilizing a library like Lodash (although this is not explicitly mentioned in the benchmark code)
* Using a different data structure, such as an array of objects or a set

It's worth noting that the choice of approach often depends on the specific use case and requirements of the project. For example, reusing the original object might be suitable if you need to maintain state between iterations, while creating a new object might be more suitable if you want to isolate properties.

Overall, MeasureThat.net provides a useful benchmarking tool for comparing different approaches to JavaScript microbenchmarks, allowing developers to evaluate and optimize their code in a fair and controlled environment.

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/605.1.15 (KHTML, like Gecko) Version/17.1 Safari/605.1.15

Browser/OS: Safari 17 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Reusing object	583.8 Ops/sec
Creating new object	0.2 Ops/sec
Using map	671.5 Ops/sec

Related benchmarks:

Reduce Object vs Map (version: 0)

Comparing performance of: Reusing object vs Creating new object vs Using map

Created: one year ago by: Guest

Jump to the latest result

Reusing object

Creating new object

Using map

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):