Benchmark: Dot assignment vs Object.assign

Tests:

Dot assignment
const name = "foo"; const amount = 123; const active = true; const target = { id: 0, }; target.name = name; target.amount = amount; target.active = active;
Object.assign
const name = "foo"; const amount = 123; const active = true; const target = { id: 0, }; Object.assign(target, { name: name, amount: amount, active: active });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Dot assignment
Object.assign

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON benchmark data and explain what is being tested, compared, and discussed.

**Benchmark Context**

The test compares two approaches to update an object: dot notation (e.g., `target.name = name;`) versus using the built-in `Object.assign()` method. This is a common optimization debate in JavaScript, with some developers advocating for the simplicity of dot notation, while others recommend using `Object.assign()` for its performance benefits.

**Test Cases**

There are two test cases:

1. **Dot Assignment**: The first test case uses dot notation to update the object:
```javascript
const target = { id: 0 };
target.name = name;
target.amount = amount;
target.active = active;
```
2. **Object.assign()**: The second test case uses `Object.assign()` to update the object:
```javascript
const target = { id: 0 };
Object.assign(target, { name: name, amount: amount, active: active });
```
**Comparison of Approaches**

The two approaches differ in their syntax and potential performance characteristics.

* **Dot Notation**: Dot notation is a more concise way to update an object's properties. However, it may lead to slower performance due to the creation of temporary objects or the need for multiple property lookups.
* **Object.assign()**: `Object.assign()` is a built-in method that copies properties from one object to another. It can be faster than dot notation because it avoids the overhead of creating temporary objects and reduces the number of property lookups.

**Pros and Cons**

Here are some pros and cons for each approach:

* **Dot Notation:**
	+ Pros:
		- Concise syntax
		- Familiar to many developers
	+ Cons:
		- May lead to slower performance due to temporary object creation or multiple property lookups
* **Object.assign()**:
	+ Pros:
		- Faster performance due to reduced temporary object creation and property lookup overhead
		- More explicit control over updates (e.g., can specify specific properties)
	+ Cons:
		- Less concise syntax compared to dot notation

**Library/Feature**

There are no external libraries or special JavaScript features being tested in this benchmark. The focus is solely on comparing the two approaches.

**Alternatives**

Other alternatives for updating objects include:

* **Object.prototype.hasOwnProperty.call()**: This method can be used with a callback function to check if an object has a specific property, and then update it using dot notation or `Object.assign()`.
* **Object.create()**: This method creates a new object based on a template object, which can be useful when updating properties of multiple objects.
* **Array.prototype.fill()** or **Array.prototype.set()**: These methods are used to update array elements, but they may not be directly applicable to object updates.

Keep in mind that these alternatives might have different performance characteristics and use cases compared to dot notation and `Object.assign()`.

Related benchmarks:

Dot assignment vs Object.assign (version: 0)

Comparing performance of: Dot assignment vs Object.assign

Created: 4 years ago by: Guest

Jump to the latest result

Dot assignment

Object.assign

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):