Benchmark: Object.assign Spread vs Object.assign.apply 2

HTML Preparation code:


<script>
  const batch = [
  { foo: 'foo' },
  { bar: 'bar' },
  { baz: 'baz' }
]
  
const spread = (target, batch) => {
  for (let i = 0; i < batch.length; i++) {
    Object.assign(target, batch[i])
  }
}

</script>

Tests:

Object.assign Spread
Object.assign(Object, ...batch)
Object.assign.apply
Object.assign.apply(Object, batch)
Spread Function
spread({}, batch)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign Spread
Object.assign.apply
Spread Function

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36 Edg/88.0.705.68

Browser/OS: Chrome 88 on Windows

View result in a separate tab

Test name	Executions per second
Object.assign Spread	2201411.8 Ops/sec
Object.assign.apply	2264318.8 Ops/sec
Spread Function	3257781.2 Ops/sec

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

LLMs can make mistakes. Check important info.

**What is being tested?**

The provided JSON represents a JavaScript microbenchmark on MeasureThat.net. The benchmark tests the performance of three different approaches to merge objects:

1. **`Object.assign()` with spread syntax**: This approach uses the spread operator (`...`) to merge multiple objects into one.
2. **`Object.assign()` with `apply()` method**: This approach uses the `apply()` method to pass the `Object.assign()` function and an array of objects as arguments.
3. **A custom "spread" function**: This approach defines a custom function named `spread()` that iterates through an array of objects and merges each object into a target object using `Object.assign()`.

**Options comparison**

The benchmark compares the performance of these three approaches:

*   **Pros and Cons:**
    *   **`Object.assign()` with spread syntax**: This approach is concise and readable. However, it may not be as efficient as other methods because it creates temporary objects.
    *   **`Object.assign()` with `apply()` method**: This approach can be more efficient than the spread syntax approach because it avoids creating intermediate objects. However, it requires more boilerplate code.
    *   **Custom "spread" function**: This approach is more readable and concise than using `apply()`. It also avoids creating temporary objects.

**Library usage**

None of the provided test cases use any external libraries.

**Special JS features or syntax**

The benchmark uses the following special JavaScript features:

*   Spread operator (`...`): Used in the "spread" function and with `Object.assign()` to merge objects.
*   `apply()` method: Used with `Object.assign()` to pass multiple arguments.

**Benchmark preparation code explanation**

The provided HTML preparation code defines a batch of objects that will be used as input for the benchmark:
```javascript
const batch = [
  { foo: 'foo' },
  { bar: 'bar' },
  { baz: 'baz' }
];
```
The script preparation code defines the custom "spread" function:
```javascript
function spread(target, batch) {
  for (let i = 0; i < batch.length; i++) {
    Object.assign(target, batch[i]);
  }
}
```

**Other alternatives**

In addition to the three approaches tested in this benchmark, other methods for merging objects using JavaScript include:

*   Using the `reduce()` method: This approach can be more efficient than the spread syntax approach because it avoids creating temporary objects.
*   Using a library like Lodash's `merge()` function: This approach provides a concise and readable way to merge objects.

Related benchmarks:

Object.assign Spread vs Object.assign.apply 2 (version: 0)

Comparing performance of: Object.assign Spread vs Object.assign.apply vs Spread Function

Created: 3 years ago by: Guest

Jump to the latest result

Object.assign Spread

Object.assign.apply

Spread Function

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):