Benchmark: Object.assign vs spread operator - 1

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:

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

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Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The test compares two approaches to merge objects in JavaScript:

1. `Object.assign()`
2. The spread operator (`...`)

The test creates two objects, `params` and `other`, using both methods. The resulting object is stored in a variable named `other`.

**Options Compared**

* `Object.assign()` vs. Spread Operator
	+ **Pros of Object.assign():**
		- Widely supported across browsers and older JavaScript versions.
		- Can be used to merge objects with existing properties, allowing for more flexibility.
		- Can be used with other methods like `merge()` or `concat()` to create a new object.
	+ **Cons of Object.assign():**
		- Requires an existing object to merge into (i.e., the first argument).
		- Can be slower due to its method call and loop iterations under the hood.

**Pros of Spread Operator:**

* Simple, concise syntax for creating new objects.
* Works with newer JavaScript versions that support it.
* Allows for more readable code by explicitly stating which properties are being copied or merged.

**Cons of Spread Operator:**

* Not widely supported across older browsers and versions (e.g., Internet Explorer).
* Limited control over the merging process compared to `Object.assign()`.

**Library/Features Used:**

None, this benchmark focuses on JavaScript core language features.

**Special JS Features/Syntax:**

The spread operator (`...`) was introduced in ECMAScript 2015 (ES6). It's a shorthand way to create new objects by copying properties from an existing object or array.

**Other Alternatives:**

Before the spread operator, developers used various techniques to achieve similar results:

1. `JSON.parse()` and `JSON.stringify()`: Not suitable for all cases, as it only works with JSON data.
2. Loops (`for...in` or `forEach()`) and object properties access (`obj.property = obj[property]`): Less readable and error-prone.

**Benchmark Results**

The latest benchmark results show that the spread operator outperforms `Object.assign()` in terms of execution frequency (ExecutionsPerSecond). However, this might be due to specific implementation details or optimizations within Chrome 83, as browsers may have varying performance characteristics.

Related benchmarks:

Object.assign vs spread operator - 1 (version: 0)

Comparing performance of: Object.assign vs spread operator

Created: 5 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):