Benchmark: Object spread vs no spread

Script Preparation code:

baseObject = {
  a: 1,
  b: 2,
  c: 3,
  d: 4,
  e: '5',
  f: '6',
  g: '7',
  h: '8',
}

Tests:

Object spread
const myObject = { ...baseObject, a: 1, bb: 2, c: 3, dd: 4, e: '5', ff: '6', g: '7', hh: '8', }
No spread
const myObject = { a: 1, b: 2, bb: 2, c: 3, dd: 4, d: 2, e: '5', ff: '6', f: '6', g: '7', hh: '8', h: '8', }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object spread
No spread

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36

Browser/OS: Chrome 115 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Object spread	499317.5 Ops/sec
No spread	949347392.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark compares two approaches to creating objects in JavaScript:

1. **Spread Syntax (Object Spread)**: This approach uses the spread operator (`...`) to create a new object by spreading an existing object into it.
2. **No Spread**: This approach creates a new object by manually copying properties from one object to another.

**Options Compared**

The two options are being compared in terms of:

* Performance (measured by `ExecutionsPerSecond`)
* Code efficiency
* Readability and maintainability

**Pros and Cons**

### Object Spread

Pros:

* More concise and readable code
* Can be more efficient for large objects with many properties

Cons:

* May be slower due to the overhead of creating a new object using the spread operator
* Less control over property creation (i.e., you can't specify the order or uniqueness of properties)

### No Spread

Pros:

* Can be faster since it doesn't involve creating a new object using the spread operator
* Allows for more control over property creation, such as specifying the order or uniqueness of properties

Cons:

* More verbose and less readable code
* May require more manual effort to copy properties correctly

**Library and Special JS Features**

In this benchmark, the `...` spread operator is used in both options. The `Object.assign()` method is not explicitly mentioned, but it's implied that it could be an alternative way to achieve the "no spread" approach.

There are no special JavaScript features or syntax being tested in this benchmark, as both approaches rely on standard JavaScript language features.

**Alternative Approaches**

Other alternatives for creating objects in JavaScript include:

* Using the `Array.prototype.reduce()` method to create a new object from an array of key-value pairs
* Utilizing library functions like `lodash` or `underscore`, which provide optimized implementations for object creation and manipulation

However, these approaches are not being tested in this specific benchmark.

**Additional Considerations**

When working with objects in JavaScript, it's essential to consider factors such as:

* Performance: How will the chosen approach impact execution time?
* Code readability and maintainability: How easy is the code to understand and modify?
* Error handling: What happens if an object property is missing or has a specific value?

By considering these factors and using best practices, developers can create efficient, readable, and maintainable object-related code in JavaScript.

Related benchmarks:

Object spread vs no spread (version: 0)

Comparing performance of: Object spread vs No spread

Created: one year ago by: Registered User

Jump to the latest result

Object spread

No spread

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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