Benchmark: JavaScript spread operator vs Object.assign performance no reference

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign({}, firstObject, secondObject);

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:

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

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Let's dive into the benchmark being tested on MeasureThat.net.

**Benchmark Definition**

The benchmark is designed to compare the performance of two ways to merge objects in JavaScript:

1. Using the spread operator (`...` syntax)
2. Using `Object.assign()` method

The benchmark involves creating two objects, `firstObject` and `secondObject`, with some sample data. Then, it creates a new object `finalObject` by merging the two input objects using one of the two methods.

**Options being compared**

The two options being compared are:

1. **Using the spread operator (`...` syntax)**:
```javascript
const finalObject = { ...firstObject, ...secondObject };
```
This method creates a new object and copies properties from `firstObject` and `secondObject` into it using the spread operator.

2. **Using `Object.assign()` method**:
```javascript
const finalObject = Object.assign({}, firstObject, secondObject);
```
This method returns a new object that is the result of merging `firstObject` and `secondObject`.

**Pros and Cons**

**Using the spread operator (`...` syntax)`**

Pros:

* More concise and readable syntax
* No need to specify the property names explicitly

Cons:

* May be slower due to the creation of a new object
* Not all browsers support it (some older versions)

**Using `Object.assign()` method**

Pros:

* Widely supported by most modern browsers
* Fast and efficient, as it uses native code

Cons:

* Requires more typing and explicit property names
* May not be as readable for some developers

**Library/dependencies**

None of the benchmark cases use any external libraries or dependencies.

**Special JS feature/syntax**

The spread operator (`...` syntax) is a relatively recent addition to JavaScript, introduced in ECMAScript 2018 (ES7). It's designed to make it easier to merge objects and arrays.

**Other alternatives**

If you wanted to use other methods for merging objects, you could also consider:

* Using `Object.assign()` with the `null` value as the second argument, which returns a new object instead of modifying the original:
```javascript
const finalObject = Object.assign({}, firstObject, secondObject);
```
However, this is not as efficient or convenient as using the spread operator.

Additionally, some older browsers may not support the spread operator. In such cases, you would need to use `Object.assign()` or another method, like using a library like Lodash (`_`.merge()).

In summary, the benchmark provides a simple and concise way to compare the performance of two ways to merge objects in JavaScript: using the spread operator and `Object.assign()`.

Related benchmarks:

JavaScript spread operator vs Object.assign performance no reference (version: 0)

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

Created: 4 years ago by: Registered User

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):