Benchmark: Object.assign vs {...newValue} 2

Tests:

With Object.assign
const row = {id: 1, label: 'asdf'}; const newRow = Object.assign({}, row, { label: `${row.label} !!!` })
With {...newValue}
const row = {id: 1, label: 'asdf'}; const newRow = {...row, label: `${row.label} !!!` }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
With Object.assign
With {...newValue}

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

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Let's dive into the benchmark test provided.

**What is being tested?**

The benchmark tests two different approaches to create a new object with updated values: using `Object.assign` and using the spread operator (`...`) with an object literal syntax.

**Test Case 1: With Object.assign**

In this test case, the code uses `Object.assign` to create a new object by copying the original object's properties (in this case, only one property: `id`) and then updating the `label` property by concatenating `' !!!'` to its current value. The resulting object is assigned to the variable `newRow`.

**Test Case 2: With {...newValue}**

In this test case, the code uses the spread operator (`...`) with an object literal syntax to create a new object by copying all properties from the original object (in this case, only one property: `id` and `label`). Then, it updates the `label` property using template literals. The resulting object is assigned to the variable `newRow`.

**Library Used**

No external library is used in these test cases.

**Special JS Feature or Syntax**

The spread operator (`...`) is used in both test cases. This feature was introduced in ECMAScript 2015 (ES6). It allows you to copy properties from an existing object into a new one, similar to how `Object.assign` works.

Here's a brief explanation of the spread operator:

* The syntax `...obj` copies all enumerable properties from `obj` into a new object.
* When used with an object literal, like `{...obj}`, it creates a shallow copy of `obj`.

**Pros and Cons**

Both approaches have their pros and cons.

* **Object.assign:**
	+ Pros:
		- Supports older browsers that don't support ES6 features (like Internet Explorer 11).
		- Can be used with non-array objects.
	+ Cons:
		- May create unnecessary intermediate copies if the original object is large or complex.
		- Can be slower for large data sets due to the overhead of creating a new object.
* **Spread Operator:**
	+ Pros:
		- More concise and expressive syntax.
		- Creates a shallow copy, which can be beneficial when working with large objects.
	+ Cons:
		- Only supported in modern browsers (ECMAScript 2015 or later).
		- May not work correctly if the original object is an array.

**Other Alternatives**

You can also use other methods to create new objects, such as:

* `Object.create`: Creates a new object that inherits from another object.
* `{}; Object.keys` : Creates a new object and then uses `Object.keys` to populate it with properties.

However, these alternatives are not directly related to the benchmark test provided.

In conclusion, this benchmark compares two approaches to create a new object with updated values: using `Object.assign` and using the spread operator (`...`) with an object literal syntax. The results show that using the spread operator is faster than using `Object.assign`.

Related benchmarks:

Object.assign vs {...newValue} 2 (version: 1)

Comparing performance of: With Object.assign vs With {...newValue}

Created: 5 years ago by: Registered User

Jump to the latest result

With Object.assign

With {...newValue}

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):