Benchmark: array to obj by key value

Tests:

one liner
const peopleArray = [ { id: 123, name: "dave", age: 23 }, { id: 456, name: "chris", age: 23 }, { id: 789, name: "bob", age: 23 }, { id: 101, name: "tom", age: 23 }, { id: 102, name: "tim", age: 23 } ] const arrayToObject = (arr, keyField) => Object.assign({}, ...arr.map(item => ({[item[keyField]]: item}))) const peopleObject = arrayToObject(peopleArray, "id")
reduced
const peopleArray = [ { id: 123, name: "dave", age: 23 }, { id: 456, name: "chris", age: 23 }, { id: 789, name: "bob", age: 23 }, { id: 101, name: "tom", age: 23 }, { id: 102, name: "tim", age: 23 } ] const arrayToObject = (array, keyField) => array.reduce((obj, item) => { obj[item[keyField]] = item return obj }, {}) const peopleObject = arrayToObject(peopleArray, "id")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
one liner
reduced

Fastest: N/A

Slowest: N/A

Latest 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 is designed to measure the performance of converting an array into an object, specifically using the `Object.assign` or `reduce` method.

**Script Preparation Code**

There is no preparation code provided for either test case. This means that the benchmark starts with a clean slate, and the execution time is solely dependent on the conversion process itself.

**Individual Test Cases**

The benchmark consists of two test cases:

1. **"one liner"`**
This test case uses the `Object.assign` method to convert the array into an object. The code snippet demonstrates how to use `map`, `reduce`, and `Object.assign` together to achieve this conversion.

Pros of using `Object.assign`:

* Concise and readable
* Widely supported in most browsers

Cons of using `Object.assign`:

* Can be slower than other methods due to the overhead of creating a new object
* May not be suitable for large datasets or complex objects

2. **"reduced"`**
This test case uses the `reduce` method to convert the array into an object. The code snippet demonstrates how to use the `reduce` method with a callback function to achieve this conversion.

Pros of using `reduce`:

* Can be more efficient than `Object.assign` for large datasets
* Allows for more control over the resulting object structure

Cons of using `reduce`:

* May require more complex code and is less readable than `Object.assign`
* Not supported in older browsers or Internet Explorer

**Library Usage**

There is no explicit library usage mentioned in either test case. However, the `Object` and `Array` prototypes are used implicitly.

**Special JS Features/Syntax**

None of the test cases use any special JavaScript features or syntax beyond what is considered standard at this point (ES6+).

**Alternatives**

If you're looking for alternative approaches to converting arrays into objects, here are a few options:

1. **Array.prototype.reduce()**: This method can be used as an alternative to `Object.assign` or `reduce`. It's more efficient than `Object.assign` but may require more complex code.
2. **Array.prototype.map() + Object.fromEntries()**: This approach uses the `map()` method to create an array of key-value pairs, which is then passed to `Object.fromEntries()`. This method can be more concise and readable than using `reduce`.
3. **Lodash's `objectAssign()` function**: If you're already relying on Lodash for other utility functions, you can use its `objectAssign` function to convert arrays into objects.

In conclusion, the choice of approach depends on your specific requirements, such as performance, conciseness, and code readability. The benchmark results provided by MeasureThat.net will help you determine which approach is most suitable for your use case.

Related benchmarks:

array to obj by key value (version: 0)

array to obj by key value

Comparing performance of: one liner vs reduced

Created: 6 years ago by: Guest

Jump to the latest result

one liner

reduced

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):