Benchmark: JavaScript reduce assign vs spread

Tests:

Object Assign
const data = [{id: 1, category: "frontend", title: "All About That Sass"}, {id: 2, category: "backend", title: "Beam me up, Scotty: Apache Beam tips"}, {id: 3, category: "frontend", title: "Sanitizing HTML: Going antibactirial on XSS attacks"}, {id: 4, category: "frontend", title: "Doing something Odd"}, {id: 5, category: "frontend", title: "How to rebuild the moon?"}]; const reduced = data.reduce((acc, item) => { acc[item.id] = item; return acc; }, {});
Object Spread
const data = [{id: 1, category: "frontend", title: "All About That Sass"}, {id: 2, category: "backend", title: "Beam me up, Scotty: Apache Beam tips"}, {id: 3, category: "frontend", title: "Sanitizing HTML: Going antibactirial on XSS attacks"}, {id: 4, category: "frontend", title: "Doing something Odd"}, {id: 5, category: "frontend", title: "How to rebuild the moon?"}]; const reduced = data.reduce((acc, item) => ({ ...acc, [item.id]: item }), {});
Object Assign Library
const data = [{id: 1, category: "frontend", title: "All About That Sass"}, {id: 2, category: "backend", title: "Beam me up, Scotty: Apache Beam tips"}, {id: 3, category: "frontend", title: "Sanitizing HTML: Going antibactirial on XSS attacks"}, {id: 4, category: "frontend", title: "Doing something Odd"}, {id: 5, category: "frontend", title: "How to rebuild the moon?"}]; const reduced = data.reduce((acc, item) => Object.assign(acc, {[item.id]: item}), {});

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object Assign
Object Spread
Object Assign Library

Fastest: N/A

Slowest: N/A

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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 Overview**

The benchmark compares three approaches to reduce an array of objects into a new object with IDs as keys:

1. **Array.prototype.reduce() with Object assignment**: This method iterates over the array, assigning each object to the accumulator using the `acc[item.id] = item` syntax.
2. **Spread operator (Object spread)**: This method uses the spread operator (`{ ...acc, [item.id]: item }`) to create a new object with the accumulator's properties spread and then add the current item as a new property.
3. **Lodash library's Object.assign()**: This benchmark uses the `Object.assign()` function from Lodash to merge the accumulator object with the current item.

**Options Compared**

The three options are compared in terms of execution speed, which is measured by the number of executions per second (ExecutionsPerSecond).

**Pros and Cons**

Here's a brief summary of each approach:

1. **Array.prototype.reduce() with Object assignment**:
	* Pros: Fast, efficient, and widely supported.
	* Cons: May not be immediately intuitive for developers without prior experience with this method.
2. **Spread operator (Object spread)**:
	* Pros: Concise, readable, and easy to understand.
	* Cons: May be slightly slower due to the overhead of creating a new object and spreading its properties.
3. **Lodash library's Object.assign()**:
	* Pros: Well-documented, widely supported, and can handle complex merge scenarios.
	* Cons: Requires an external library, which may not be desirable for all projects.

**Other Considerations**

When choosing between these approaches, consider the following:

* If you need to perform complex merges or have a large dataset, Lodash's `Object.assign()` might be a good choice due to its flexibility and support.
* For simple cases where readability is crucial, the spread operator (Object spread) might be the best option.
* In general, if you're familiar with the `Array.prototype.reduce()` method, it's likely the fastest and most efficient option.

**Library**

In this benchmark, Lodash is used as a library for its `Object.assign()` function. Lodash provides a utility belt of functions that can simplify common tasks in JavaScript development.

I hope this explanation helps!

Related benchmarks:

JavaScript reduce assign vs spread (version: 0)

Comparing performance of: Object Assign vs Object Spread vs Object Assign Library

Created: 4 years ago by: Guest

Jump to the latest result

Object Assign

Object Spread

Object Assign Library

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):