Benchmark: JavaScript spread operator vs Object.assign performance fixed 3

Script Preparation code:

var firstObject = {
    sampleData: 'Hello world'
}
var secondObject2 = {
    moreData: 'foo bar'
}
var secondObject3 = {
    moreData: 'foo bar'
}
var secondObject4 = {
    moreData: 'foo bar'
}
var secondObject5 = {
    moreData: 'foo bar'
}
var secondObject6 = {
    moreData: 'foo bar'
}
var secondObject7 = {
    moreData: 'foo bar'
}

Tests:

Using the spread operator
const finalObject = { ...firstObject, ...secondObject2, ...secondObject3, ...secondObject4, ...secondObject5, ...secondObject6, ...secondObject7, };
Using Object.assign
const finalObject = Object.assign({}, secondObject2, secondObject3, secondObject4, secondObject5, secondObject6, secondObject7,);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using Object.assign

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

**Benchmark Explanation**

The provided benchmark measures the performance difference between two methods: using the JavaScript spread operator and `Object.assign` to merge multiple objects into one.

**Options Being Compared**

Two options are being compared:

1. **Using the spread operator**: This method uses the syntax `{...obj1, ...obj2, ...objN}` to create a new object with properties from each of the input objects.
2. **Using `Object.assign`**: This method takes multiple objects as arguments and returns a new object that contains all the key-value pairs from the input objects.

**Pros and Cons**

### Using the Spread Operator

Pros:

* More concise and readable syntax
* Can be used to create new objects with dynamic number of properties
* Faster performance compared to `Object.assign` (in this benchmark)

Cons:

* Limited compatibility with older browsers (pre-ES6)
* May not work as expected if object keys are not unique or if there are circular references

### Using `Object.assign`

Pros:

* Wide browser compatibility (since ES5)
* Can be used to update existing objects
* Can handle complex cases like merging objects with nested properties

Cons:

* Less readable syntax compared to the spread operator
* May require additional steps to create a new object instead of using `Object.assign`
* Slower performance compared to the spread operator (in this benchmark)

**Library and Special JS Features**

In this benchmark, no special JavaScript features or libraries are used. The test cases only rely on built-in JavaScript methods.

**Other Alternatives**

Besides the two options being compared, other alternatives for merging objects include:

* **Array.prototype.reduce()**: Can be used to merge multiple objects by reducing them into a single object.
* **Lodash.merge()**: A popular utility library that provides a `merge` function for merging objects.
* **Object.create() + Object.assign()**: Can be used to create a new object and then update it with properties from other objects.

These alternatives may have different performance characteristics, compatibility issues, or readability concerns compared to the spread operator and `Object.assign`.

Related benchmarks:

JavaScript spread operator vs Object.assign performance fixed 3 (version: 0)

Comparing performance of: Using the spread operator vs Using Object.assign

Created: 3 years ago by: Guest

Jump to the latest result

Using the spread operator

Using 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):