Benchmark: Object.assign vs spread operator 4

Tests:

Object.assign
var obj1 = {a: 2}; var obj2 = { b:"hello", c: true, d:7 }; var result = Object.assign(obj1, obj2);
spread operator
var obj1 = {a: 2}; var obj2 = { b:"hello", c: true, d:7 }; var result = {...obj1, ...obj2};

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

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Test case name	Result
Object.assign
spread operator

Fastest: N/A

Slowest: N/A

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

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**Overview of the Benchmark**

The provided benchmark compares the performance of `Object.assign` and the spread operator (`...`) in JavaScript when used to merge two objects.

**What is tested?**

In this benchmark, two individual test cases are defined:

1. `Object.assign`: This function takes multiple source objects as arguments and returns a new object that contains the merged properties from each source.
2. **Spread Operator (`...`)**: This operator is used to create a new object by spreading the properties of an existing object.

**Options compared**

The benchmark compares the performance of these two options in the following scenarios:

* Merging two small objects (e.g., `{a: 2}`, `{b: "hello"}`) using `Object.assign` and the spread operator.
* Merging two larger objects (e.g., `{a: 2}`, `{b: "hello", c: true, d: 7}`) using `Object.assign` and the spread operator.

**Pros and Cons of each approach**

1. **`Object.assign()`**
	* Pros:
		+ Widely supported in older browsers.
		+ Can be used with multiple source objects.
		+ Returns a new object, which is useful for immutable data structures.
	* Cons:
		+ Can be slower due to the overhead of function calls and property iteration.
		+ May not perform as well on large datasets.
2. **Spread Operator (`...`)**
	* Pros:
		+ Faster execution time, especially for small objects.
		+ More concise syntax compared to `Object.assign()`.
		+ Native support in modern browsers.
	* Cons:
		+ Not supported in older browsers (before Chrome 42).
		+ Can be slower for large datasets.

**Library and Special JavaScript Features**

The benchmark does not use any external libraries. However, it relies on the native JavaScript spread operator (`...`), which was introduced in ECMAScript 2018 (ES2018).

**Other Considerations**

* The benchmark is designed to test the performance of both options under different scenarios.
* It provides a good example for developers who need to choose between `Object.assign()` and the spread operator.

**Alternatives**

If you want to write your own implementation or use alternative methods, here are some alternatives:

1. **Using `Array.prototype.reduce()`**: You can use the `reduce()` method of arrays to merge objects. For example: `{...obj1.reduce((acc, curr) => ({ ...acc, ...curr }), {}), ...obj2.reduce((acc, curr) => ({ ...acc, ...curr }), {})}`.
2. **Using a library like Lodash**: If you need more advanced merging capabilities or want to avoid the spread operator, consider using a library like Lodash, which provides a `merge()` function.

Keep in mind that these alternatives may have different performance characteristics and use cases compared to the spread operator and `Object.assign()`.

Related benchmarks:

Object.assign vs spread operator 4 (version: 0)

Comparing performance of: Object.assign vs spread operator

Created: 3 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):