Benchmark: Object.assign vs spread operator - Jay

Tests:

Object.assign
var params = { b:"hello", c: true, d:7 }; var other = Object.assign({ a: 2 }, params);
spread operator
var params = { b:"hello", c: true, d:7 }; var other = { a: 2, ...params };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
spread operator

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.

Let's break down the provided benchmark and explain what's being tested, the options compared, their pros and cons, and other considerations.

**Benchmark Definition**
The benchmark is defined in JSON format, which includes the name, description, script preparation code, and HTML preparation code. However, in this case, all fields are empty or null, indicating that no specific details about the benchmark are provided.

**Individual Test Cases**
There are two test cases:

1. **Object.assign**: This test case uses the `Object.assign` method to merge an object with a set of key-value pairs.
2. **Spread Operator (REST Parameter)**: This test case uses the spread operator (`...`) to merge an object with a set of key-value pairs.

**What is being tested?**
The benchmark tests the performance difference between using the `Object.assign` method and the spread operator in JavaScript. Both methods are used to merge objects, but they have different syntax and behavior.

**Options compared**

* **Option 1: Object.assign**: This method takes an object as its first argument and an iterable (like an array or another object) as its second argument.
```javascript
var params = { b: "hello", c: true, d: 7 };
var other = Object.assign({ a: 2 }, params);
```
Pros:

* Widespread support across browsers and environments.
* Can be used to merge multiple iterables.

Cons:

* Requires creating an object as its first argument.
* May have performance overhead due to the additional creation step.

* **Option 2: Spread Operator (REST Parameter)**: This method uses the spread operator (`...`) to extract properties from an iterable and merge them with another object.
```javascript
var params = { b: "hello", c: true, d: 7 };
var other = { a: 2, ...params };
```
Pros:

* More concise syntax compared to `Object.assign`.
* Does not require creating an object as its first argument.

Cons:

* Less widespread support across browsers and environments (Chrome 73 is the only browser listed in the benchmark results).
* May have performance overhead due to the creation of a new object.

**Other Considerations**

* **Library usage**: There are no libraries used in this benchmark.
* **Special JS features/syntax**: The spread operator (`...`) was introduced in ECMAScript 2015 (ES6), which is why it's not supported by all browsers and environments.

**Benchmark Results**
The latest benchmark results show the performance difference between using `Object.assign` and the spread operator. However, without more information about the specific use cases or scenarios being tested, it's difficult to draw conclusions about the performance differences.

**Alternatives**

* **Other methods**: Other methods for merging objects include `forEach`, `for...in`, and `reduce`. However, these methods may have different performance characteristics compared to `Object.assign` and the spread operator.
* **Alternative benchmarks**: Benchmarks that compare the performance of other JavaScript features or syntax, such as async/await or promises, might provide more interesting results.

I hope this explanation helps!

Related benchmarks:

Object.assign vs spread operator - Jay (version: 0)

Comparing performance of: Object.assign vs spread operator

Created: 6 years ago by: Guest

Jump to the latest result

Object.assign

spread operator

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):