Benchmark: Assignment vs Object.assign - corrected

Tests:

using direct assignment
let ob = { key1: 'hello', key2: 'world', key3: 'foo', key4: 'bar' } let ob2 = { key2: 'cat', key4: 'fish' } let res = { key1: ob.key1, key2: ob2.key2, key3: ob.key3, key4: ob2.key4 }
using Object.assign
let ob = { key1: 'hello', key2: 'world', key3: 'foo', key4: 'bar' } let ob2 = { key2: 'cat', key4: 'fish' } let res = Object.assign(ob2,ob)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
using direct assignment
using Object.assign

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:106.0) Gecko/20100101 Firefox/106.0

Browser/OS: Firefox 106 on Linux

View result in a separate tab

Test name	Executions per second
using direct assignment	328743808.0 Ops/sec
using Object.assign	10048549.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is tested, compared, and some considerations for each approach.

**Benchmark Definition**
The benchmark compares two ways of assigning values to an object: using direct assignment (`let res = {...}`) and using `Object.assign()`.

**Options Compared**

1. **Direct Assignment**: This approach uses a single expression to create the new object `res`, where each property is assigned from one object to another.
2. **Object.assign()**: This approach uses a function to merge two objects, creating a new object with properties from both input objects.

**Pros and Cons of Each Approach**

1. **Direct Assignment**
	* Pros:
		+ Can be more concise and readable for simple cases.
		+ May have performance benefits due to fewer function calls.
	* Cons:
		+ May lead to typos or errors if not carefully crafted.
		+ Not designed for complex object merging, which can result in unexpected behavior.
2. **Object.assign()**
	* Pros:
		+ Designed for complex object merging and provides more control over the merge process.
		+ Less prone to typos and errors compared to direct assignment.
	* Cons:
		+ May be less readable due to function call overhead.
		+ Can lead to slower performance if not optimized.

**Library Used**
The benchmark uses `Object.assign()` from the JavaScript standard library, which provides a way to merge two or more objects into a new object.

**Special JS Features/Syntax**
There are no special JS features or syntax used in this benchmark.

**Other Alternatives**

1. **JSON Merge Patch**: Another approach for merging objects is using the JSON Merge Patch (JMP) algorithm. This approach is designed to be more efficient and concise than `Object.assign()`.
2. **Array.prototype.reduce()**: You can also merge objects using `Array.prototype.reduce()`, which provides a functional programming style for combining arrays of key-value pairs.

Here's an example of how you could implement the benchmark using `Array.prototype.reduce()`:

```javascript
let ob = {
  key1: 'hello',
  key2: 'world',
  key3: 'foo',
  key4: 'bar'
};

let ob2 = {
  key2: 'cat',
  key4: 'fish'
};

let res = Object.keys(ob).reduce((acc, key) => {
  acc[key] = (ob[key] || '') === '' ? (ob2[key] || '') : ob[key];
  return acc;
}, {});

console.log(res);
```

Keep in mind that this implementation is not as concise or readable as `Object.assign()` and may have performance implications depending on the size of the input objects.

Related benchmarks:

Assignment vs Object.assign - corrected (version: 0)

compare assignment to object.assign

Comparing performance of: using direct assignment vs using Object.assign

Created: 2 years ago by: Guest

Jump to the latest result

using direct assignment

using Object.assign

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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