Benchmark: Performance : Object.assign vs Spread operator vs Vanilla

Tests:

Object.assign
var params = { b:"hello", c: true, d:7, e: ['foo', 'bar'] }; var other = Object.assign({ a: 2 }, params);
Spread Operator
var params = { b:"hello", c: true, d:7, e: ['foo', 'bar'] }; var other = { a: 2, ...params };
Vanilla Update
var params = { b:"hello", c: true, d:7, e: ['foo', 'bar'] }; params.a = 2; params.b = "NEW TEXT"; params.c = false; params.d = 10; params.e[0] = 'bar'; params.e[1] = 'foo';

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
Spread Operator
Vanilla Update

Fastest: N/A

Slowest: N/A

Latest run results:

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

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I'll explain the benchmark and its results in detail.

**Benchmark Overview**

The benchmark compares the performance of three approaches: `Object.assign`, the spread operator (`...`), and manual assignment using vanilla JavaScript.

**Options Compared**

* `Object.assign`: A method that takes an object as an argument and merges it with another object, returning a new object.
* Spread Operator (`...`): A syntax that allows creating a new object by spreading the properties of an existing object or array into a new object.
* Vanilla Update: A manual approach where each property is assigned individually using dot notation.

**Pros and Cons**

1. `Object.assign`:
	* Pros: Easy to read and write, widely supported, and can handle complex objects with nested structures.
	* Cons: Can be slower than the spread operator for simple cases, and may create unnecessary intermediate objects.
2. Spread Operator (`...`):
	* Pros: Fast and efficient, produces minimal overhead, and is generally faster than `Object.assign`.
	* Cons: May require extra parentheses to use correctly, and can lead to confusing code if not used carefully.
3. Vanilla Update:
	* Pros: No additional syntax or performance overhead, easy to read and understand.
	* Cons: Can be slower due to the need for explicit property assignments, and may become cumbersome with large numbers of properties.

**Library Used**

None mentioned in the provided benchmark definition. However, `Object.assign` is a built-in method that comes with JavaScript, so no external library is required.

**Special JS Feature or Syntax**

The spread operator (`...`) was introduced in ECMAScript 2015 (ES6) and has been widely adopted since then. It provides a concise way to create new objects by spreading the properties of existing objects or arrays.

**Benchmark Results**

The benchmark shows the performance results for each test case:

* `Vanilla Update`: The fastest approach, with an execution rate of approximately 1.04 executions per second.
* `Object.assign`: Slightly slower than vanilla update, with an execution rate of around 0.75 executions per second.
* `Spread Operator`: The slowest approach, with an execution rate of approximately 0.28 executions per second.

**Alternatives**

If you want to explore alternative approaches or libraries for object assignment, here are some options:

1. Lodash's `_.assign()`: A popular utility library that provides a fast and flexible way to merge objects.
2. Immutable.js: A library that provides immutable data structures and methods, including a version of the spread operator (`...`) optimized for performance.
3. JavaScript's built-in `Object.create()` method: An alternative approach to merging objects using the spread operator.

Keep in mind that these alternatives may come with additional dependencies or overhead, so it's essential to evaluate their trade-offs based on your specific use case and requirements.

Related benchmarks:

Performance : Object.assign vs Spread operator vs Vanilla (version: 0)

Comparing performance of: Object.assign vs Spread Operator vs Vanilla Update

Created: 7 years ago by: Guest

Jump to the latest result

Object.assign

Spread Operator

Vanilla Update

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):