Benchmark: Spread vs Assign benchmark 2

Tests:

Basic object spread
const obj = { foo: 1, bar: 2 }; const finalObject = { baz: 3, ...obj };
Basic assign operator
const obj = { foo: 1, bar: 2 }; const finalObject = Object.assign({baz: 3}, obj);
Assign with empty object
const obj = { foo: 1, bar: 2 }; Object.assign({}, obj, { baz: 3 });
Spread operator with two existing objects
const obj = { foo: 1, bar: 2 }; const obj2 = { baz: 3 }; const finalObject = {...obj2, ...obj };
Object assign with two existing objects
const obj = { foo: 1, bar: 2 }; const obj2 = { baz: 3 }; const finalObject = Object.assign(obj2, obj );

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Basic object spread
Basic assign operator
Assign with empty object
Spread operator with two existing objects
Object assign with two existing objects

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

**Benchmark Purpose:**
The `MeasureThat.net` benchmark tests how JavaScript engines handle object spread and assignment operations in various scenarios. Specifically, it compares different approaches to create a new object by spreading or assigning existing objects.

**Options Compared:**

1. **Basic Object Spread**: This option uses the syntax `{ ...obj }`, where `obj` is an existing object being spread into a new object.
2. **Basic Assign Operator**: This option uses the syntax `Object.assign({ baz: 3 }, obj)`, where `obj` is an existing object being assigned to a new object with an initial value of `{ baz: 3 }`.
3. **Assign with Empty Object**: This option uses the syntax `Object.assign({}, obj, { baz: 3 })`, where `obj` is an existing object and an empty object `{}` is used as the target for assignment.
4. **Spread Operator with Two Existing Objects**: This option uses the syntax `{ ...obj2, ...obj }`, where both `obj2` and `obj` are existing objects being spread into a new object.
5. **Object Assign with Two Existing Objects**: This option uses the syntax `Object.assign(obj2, obj)`, where both `obj2` and `obj` are existing objects being assigned to a new object.

**Pros and Cons:**

* **Basic Object Spread**: Pros - concise and readable; Cons - may not be supported in older browsers.
* **Basic Assign Operator**: Pros - widely supported across browsers; Cons - less readable than the spread syntax.
* **Assign with Empty Object**: Pros - allows for more control over the assignment process; Cons - requires a second object as an argument.
* **Spread Operator with Two Existing Objects**: Pros - concise and readable; Cons - may not be supported in older browsers.
* **Object Assign with Two Existing Objects**: Pros - widely supported across browsers; Cons - less readable than the spread syntax.

**Libraries Used:**
In this benchmark, `Object.assign()` is used as a library function to facilitate object assignment. It's a standard method for assigning properties from one or more source objects to a target object.

**Special JS Features/Syntax:**
This benchmark doesn't explicitly use any special JavaScript features or syntax beyond the standard syntax for creating new objects using spread and assign operators.

**Other Considerations:**

* Browser Support: The benchmark is run on Chrome Mobile 89, which may not reflect the behavior in other browsers.
* Device Platform: The test runs on a mobile device with Android 5.1.1, which might introduce variations due to mobile-specific considerations.

**Alternatives:**
To measure object spread and assignment performance, you could use alternative approaches such as:

* Using `JSON.parse(JSON.stringify(obj))` for basic spreading
* Implementing a custom spread function using recursion or iteration
* Testing with other libraries or frameworks that provide similar functionality

Keep in mind that each approach has its own trade-offs and potential drawbacks. The choice of method depends on the specific requirements and constraints of your project.

If you have any further questions or would like more information on JavaScript performance optimization, feel free to ask!

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Linux; Android 5.1.1; SM-J200H) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.105 Mobile Safari/537.36

Browser/OS: Chrome Mobile 89 on Android 5.1.1

View result in a separate tab

Test name	Executions per second
Basic object spread	640396.2 Ops/sec
Basic assign operator	232981.8 Ops/sec
Assign with empty object	208497.2 Ops/sec
Spread operator with two existing objects	44896.6 Ops/sec
Object assign with two existing objects	260082.2 Ops/sec

Related benchmarks:

Spread vs Assign benchmark 2 (version: 0)

Comparing performance of: Basic object spread vs Basic assign operator vs Assign with empty object vs Spread operator with two existing objects vs Object assign with two existing objects

Created: 3 years ago by: Registered User

Jump to the latest result

Basic object spread

Basic assign operator

Assign with empty object

Spread operator with two existing objects

Object assign with two existing objects

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):