Benchmark: Object.assign vs spread operator

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 };
jQuery extend
var params = { b:"hello", c: true, d:7 }; var other = $.extend({ a: 2 }, params);
Manual Update
var params = { b:"hello", c: true, d:7 }; params.b = "NEW TEXT";

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
spread operator
jQuery extend
Manual Update

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark and its options.

**Benchmark Overview**

The benchmark, named "Object.assign vs spread operator", compares the performance of four different approaches for assigning properties to an object: `Object.assign`, the spread operator (`...`), jQuery's `$extend` method, and manual property updates.

**Options Compared**

1. **`Object.assign`**: This method takes two arguments: the target object and a source object. It returns the target object with the source object's properties added to it.
2. **Spread Operator (`...`)**: This operator allows you to create a new object by spreading the properties of an existing object into a new object.
3. **jQuery `$extend` method**: This method is part of the jQuery library and is used to extend an existing object with new properties from another object.
4. **Manual Update**: This approach involves updating individual properties on the target object.

**Pros and Cons of Each Approach**

1. **`Object.assign`**:
	* Pros: Simple, widely supported, and efficient.
	* Cons: Can be slower than other approaches for large objects or deep assignments.
2. **Spread Operator (`...`)**:
	* Pros: Modern, concise, and fast.
	* Cons: May not work as expected in older browsers or environments with limited support for the spread operator.
3. **jQuery `$extend` method**:
	* Pros: Part of a widely used library, easy to use, and can handle complex assignments.
	* Cons: Requires jQuery to be loaded, which may add unnecessary overhead.
4. **Manual Update**:
	* Pros: Simple and efficient for small objects or simple updates.
	* Cons: Can be tedious and error-prone for large objects or complex updates.

**Library: jQuery**

The `$.extend` method is part of the jQuery library. It takes two arguments: the target object and an object containing key-value pairs to assign to the target object.

In the benchmark, jQuery is loaded on the page, but its overhead is not explicitly measured. However, it's likely that including jQuery adds a small performance penalty compared to using native JavaScript methods like `Object.assign`.

**Special JS Features/Syntax**

The spread operator (`...`) is a modern JavaScript feature introduced in ES6 (2015). It allows you to create a new object by spreading the properties of an existing object into a new object. This syntax is not supported in older browsers or environments without ES6 support.

In the benchmark, both `Object.assign` and the spread operator are used for assignment, but they have different performance characteristics due to their implementation details and browser support.

**Benchmark Results**

The latest benchmark results show that:

* Manual Update has the highest execution rate (807M executions per second).
* The Spread Operator has a moderate execution rate (207M executions per second).
* jQuery `$extend` method has a lower execution rate (206M executions per second).
* `Object.assign` has the lowest execution rate (154M executions per second).

These results suggest that Manual Update is the fastest approach, followed by the Spread Operator and then jQuery's `$extend` method. However, it's essential to note that these results are specific to this benchmark and may not generalize to other scenarios.

**Other Alternatives**

If you're interested in exploring alternative approaches for object assignment, consider:

* Using a library like Lodash or Ramda, which provide more functional programming-style APIs for object manipulation.
* Implementing your own custom `assign` method using native JavaScript methods like `Object.create()` and `Object.assign()`.
* Using other libraries like Underscore.js or Lo-Dash, which offer alternative approaches to object assignment.

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36

Browser/OS: Chrome 66 on Mac OS X 10.13.3

View result in a separate tab

Test name	Executions per second
Object.assign	1546504.4 Ops/sec
spread operator	2079553.5 Ops/sec
jQuery extend	2065251.0 Ops/sec
Manual Update	807408768.0 Ops/sec

Related benchmarks:

Object.assign vs spread operator (version: 0)

Comparing performance of: Object.assign vs spread operator vs jQuery extend vs Manual Update

Created: 6 years ago by: Guest

Jump to the latest result

Object.assign

spread operator

jQuery extend

Manual Update

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):