Benchmark: JS cloning benchmark

Tests:

Object.assign
var params = { a: 1, b:"hello", c: true, d:7, e: "test", f: "getting", g: "longer", h: false, i: "but more realistic for enterprise development" }; var other = Object.assign({ id: "5d493b95-6255-4662-8de5-875370997a7c" }, params);
Spread
var params = { a: 1, b:"hello", c: true, d:7, e: "test", f: "getting", g: "longer", h: false, i: "but more realistic for enterprise development" }; var other = { id: "5d493b95-6255-4662-8de5-875370997a7c", ...params };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
Spread

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object.assign	13542296.0 Ops/sec
Spread	10812914.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring the performance of different approaches to cloning objects in JavaScript is an interesting benchmark.

**Benchmark Description**

The test case measures the time taken by two approaches:

1. `Object.assign()`: This method creates a new object and copies all enumerable own properties from one or more source objects to a target object.
2. `Spread Operator (`: This syntax creates a new object with all enumerable own properties from an existing object, using the spread operator (`{ ...obj }`).

**Options Compared**

The benchmark compares the performance of these two approaches:

* **Object.assign()**: Pros:
	+ Well-supported in most browsers and JavaScript engines.
	+ Can handle nested objects.
	+ Returns a new object with all properties from the source object.
* **Spread Operator (`)**: Cons:
	+ Only supported in modern browsers (Chrome 109) and some Node.js versions.
	+ May have performance overhead due to syntax parsing.
	+ Only works for shallow cloning, not handling nested objects.

**Pros and Cons of Each Approach**

* **Object.assign()**:
	+ Pros: widely supported, efficient for shallow cloning.
	+ Cons: can be verbose with multiple source objects.
* **Spread Operator (`)**:
	+ Pros: concise syntax, easier to read.
	+ Cons: limited support, may have performance overhead.

**Library Usage**

In the provided benchmark definition, there is no explicit library usage. However, if a library like Lodash or Underscore.js were used, it might affect the cloning behavior and performance.

**Special JS Features or Syntax**

The test case uses the spread operator (`)** for cloning objects, which is a relatively recent JavaScript feature (introduced in ECMAScript 2018). This syntax is supported in modern browsers and some Node.js versions but may not work in older environments.

**Other Alternatives**

If `Object.assign()` or the spread operator (`)** are not suitable options, other alternatives for cloning objects include:

* Using a library like Lodash's `cloneDeep()`
* Implementing a custom cloning function using recursion or iteration
* Using a JavaScript framework or utility library that provides an efficient cloning mechanism

In summary, the benchmark measures the performance of two approaches to cloning objects in JavaScript: `Object.assign()` and the spread operator (`)**. The choice of approach depends on the specific requirements, such as supporting older browsers or handling nested objects.

Related benchmarks:

JS cloning benchmark (version: 0)

Comparing performance of: Object.assign vs Spread

Created: 7 years ago by: Guest

Jump to the latest result

Object.assign

Spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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