Benchmark: Object Spread vs Assign

Tests:

Object Spread
const object = {}; for (i = 0; i < 30; i++) { object[`${i}_key`, i]; } const newObject = {...object}
Object Assign
const object = {}; for (i = 0; i < 30; i++) { object[`${i}_key`, i]; } const newObject = Object.assign({}, object)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object Spread
Object Assign

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 dive into the explanation of the provided JSON benchmark.

**Benchmark Definition:**

The benchmark is focused on comparing two approaches for creating a new object by copying an existing one:

1. **Object Spread (Using Rest Spreading)**: This approach uses the rest spreading operator (`{...object}`) to create a shallow copy of the original object.
2. **Object Assign**: This approach uses the `Object.assign()` method to create a deep copy of the original object.

**Options Compared:**

* Rest spreading vs Object assign

**Pros and Cons:**

* **Rest Spreading (Object Spread)**:
	+ Pros:
		- Faster execution time, as it only creates a shallow copy of the object.
		- Less memory allocation required, resulting in lower overhead.
	+ Cons:
		- May not work correctly for nested objects or arrays.
		- Limited support in older browsers (prior to Chrome 49).
* **Object Assign**:
	+ Pros:
		- Works with any type of object, including nested ones.
		- Widely supported across modern browsers and older versions.
	+ Cons:
		- Generally slower execution time due to the need for deep copying.
		- Requires more memory allocation.

**Library/Technology Used:**

In both test cases, no specific libraries or frameworks are mentioned. However, it's worth noting that Object Assign uses the `Object.assign()` method, which is a built-in JavaScript function.

**Special JS Features/Syntax:**

The benchmark makes use of rest spreading (`{...object}`) and template literals (`${i}_key`, i), which are features introduced in ECMAScript 2015 (ES6). These features allow for concise and readable code, but may not be supported in older JavaScript environments.

**Alternative Approaches:**

Other approaches to create a new object by copying an existing one include:

* Using the `JSON.parse(JSON.stringify(obj))` method, which creates a deep copy of the original object.
* Utilizing a library like Lodash's `cloneDeep()` function, which provides a robust and customizable way to create deep copies.

Keep in mind that these alternative approaches may have their own trade-offs in terms of performance, memory usage, and compatibility with different browsers or environments.

Related benchmarks:

Object Spread vs Assign (version: 0)

Comparing performance of: Object Spread vs Object Assign

Created: 5 years ago by: Guest

Jump to the latest result

Object Spread

Object Assign

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):