Benchmark: Object.assign vs direct assignment 2

Script Preparation code:

var data = {};
var props = {};
for(var i = 0; i < 10000; i++)
{
   props[i] = i;
}

Tests:

Direct Assignment
for(var prop in props) { data[prop] = props[prop]; }
Object.assign
Object.assign(data, props);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Direct Assignment
Object.assign

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 benchmark and explain what's being tested.

**Benchmark Definition**

The provided JSON defines two microbenchmarks:

1. `Object.assign vs direct assignment 2`: This benchmark compares the performance of using the `Object.assign()` method versus direct assignment to copy an object.
2. The individual test cases:
	* `Direct Assignment`
	* `Object.assign`

**Test Case: Direct Assignment**

This test case uses a loop that iterates 10,000 times, assigning each iteration number to a property on an object called `data`. This is done using the syntax `data[prop] = props[prop];`, where `prop` is the current iteration number.

**Test Case: Object.assign**

This test case uses the `Object.assign()` method to copy the contents of an object called `props` into another object called `data`.

**Library Used: Object.assign()**

The `Object.assign()` method is a built-in JavaScript function that allows you to merge two or more objects into a new object. It's commonly used for copying objects, updating existing properties, and creating new objects from existing ones.

In this benchmark, the performance of using `Object.assign()` versus direct assignment is being compared. Direct assignment uses a simple syntax like `data[prop] = props[prop];`, while `Object.assign()` provides a more concise way to achieve the same result.

**Pros and Cons**

**Direct Assignment:**

Pros:

* Easy to understand and implement
* No additional function call overhead

Cons:

* Can be slower due to the iteration over the object's properties
* May not handle complex object structures as efficiently as `Object.assign()`

**Object.assign():**

Pros:

* More concise syntax
* Handles complex object structures more efficiently
* Less prone to errors due to automatic property merging

Cons:

* Requires calling an additional function, which may introduce overhead
* Can be less intuitive for developers who aren't familiar with the method

**Other Considerations:**

When evaluating these two approaches, consider the specific use case and performance requirements. If you need to copy simple objects with a small number of properties, direct assignment might be sufficient. However, if you're working with complex object structures or need to update existing properties, `Object.assign()` is likely a better choice.

**Special JavaScript Feature/Syntax:**

There's no specific special feature or syntax mentioned in the benchmark that requires additional explanation. Both test cases use standard JavaScript syntax and built-in functions.

**Alternatives:**

Other alternatives for copying objects include:

* Using `lodash` library's `pick()` method
* Using a custom function like `mergeObjects()`
* Using a library like `immer` for immutable data structures

However, in this specific benchmark, `Object.assign()` is being compared to direct assignment, which eliminates these alternatives from consideration.

Related benchmarks:

Object.assign vs direct assignment 2 (version: 0)

Comparing performance of: Direct Assignment vs Object.assign

Created: 5 years ago by: Guest

Jump to the latest result

Direct 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):