Benchmark: object creation spread vs init

Tests:

spread
const x1 = {x1: 1}; const x2 = {x2: 1}; const x3 = {x3: 1}; const x4 = {x4: 1}; const result = { ...x1, ...x2, ...x3, ...x4 }
initializing
const result = { x1: 1, x2: 1, x3: 1, x4: 1 }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread
initializing

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Windows

View result in a separate tab

Test name	Executions per second
spread	15726475.0 Ops/sec
initializing	158054624.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring JavaScript performance is an essential task, especially when it comes to optimizing code for different scenarios.

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

**Benchmark Definition**

The benchmark definition json represents two test cases:

1. `object creation spread vs init`
2. `const x1 = {x1: 1};` (initialized object)
3. `const x2 = {x2: 1};` (initialized object, not shown in the benchmark but used in the `spread` case)
4. `const x3 = {x3: 1};` (initialized object, not shown in the benchmark but used in the `spread` case)
5. `const x4 = {x4: 1};` (initialized object, not shown in the benchmark but used in the `spread` case)

The two main test cases are:

**a. Initializing**

This test case creates a single object with four properties (`x1`, `x2`, `x3`, and `x4`) and assigns values to each property using the syntax: `const result = { x1: 1, x2: 1, x3: 1, x4: 1 }`. The goal is to measure the performance of creating an object with a fixed number of properties using this syntax.

**b. Object creation spread**

This test case creates four separate objects (`x1`, `x2`, `x3`, and `x4`) and then uses the spread operator (`...`) to merge these objects into a single object: `const result = { ...x1, ...x2, ...x3, ...x4 }`. The goal is to measure the performance of creating an object using this syntax.

**Options compared**

The two approaches are:

* **Initialized object**: Creating an object with a fixed number of properties and assigning values directly.
* **Object creation spread**: Creating separate objects and merging them using the spread operator.

**Pros and Cons**

**Initialized Object:**

Pros:

* More readable code
* Easier to maintain and modify

Cons:

* Can be slower due to the repeated assignment of property values

**Object Creation Spread:**

Pros:

* More concise code
* Efficient way to merge objects with similar properties

Cons:

* Less readable code (can be harder to understand)
* May lead to performance issues if not implemented correctly

**Library and Special JS feature used**

In this benchmark, the spread operator (`...`) is used, which is a JavaScript syntax introduced in ECMAScript 2018. The library used here is not explicitly mentioned.

**Considerations**

When deciding between these approaches, consider the following:

* Readability: If code readability is more important than performance, use initialized objects.
* Performance: If performance is critical and object properties have similar values (e.g., `const result = { ...x1, x2: 2, ...x3 }`), use object creation spread.

**Other alternatives**

If you're looking for alternative approaches or tools to measure JavaScript performance, consider:

* V8 Benchmark Suite
* JSHint's Performance Test
* Google Chrome's DevTools (includes the Web Performance section)

These resources can provide insights into various JavaScript performance topics, including optimization techniques and benchmarking methodologies.

Related benchmarks:

object creation spread vs init (version: 0)

Comparing performance of: spread vs initializing

Created: one year ago by: Registered User

Jump to the latest result

spread

initializing

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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