Benchmark: Object Creation vs Variable

Tests:

object
var hello = { what: [], wh: 0, wo: 0 }
var
var what = []; var wh = 0; var wo = 0;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
object
var

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; rv:138.0) Gecko/20100101 Firefox/138.0

Browser/OS: Firefox 138 on Windows

View result in a separate tab

Test name	Executions per second
object	747858048.0 Ops/sec
var	696067456.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

The provided JSON represents a benchmark that tests two approaches to creating objects: using variables (`var`) and using an object literal syntax (`{}`). The goal is to measure which approach is faster.

**Variables vs Object Literal Syntax**

In JavaScript, when you declare a variable, it doesn't automatically create an object with the same properties. You need to explicitly use the assignment operator (`=`) to assign values to variables that are also used as property names in objects.

Here's what's being compared:

1. **`var hello = { ... }`**: This creates an object literal syntax, where the variable `hello` is assigned a value that is an object with properties `what`, `wh`, and `two`. The assignment itself doesn't create these properties; it simply assigns the given values to the existing properties.
2. **`var what = []; var wh = 0; var wo = 0;`**: This creates variables `what`, `wh`, and `wo`, which are then assigned array and numeric values. When using these variables as property names, they don't automatically create an object with the given properties.

**Pros and Cons**

* **Object Literal Syntax (using `{}`)**:
	+ Pros:
		- Creates a clean and readable object definition.
		- Can be more efficient when creating objects from scratch.
	+ Cons:
		- Requires the use of the assignment operator (`=`) to create properties, which can add unnecessary overhead.
* **Variable-based Approach (using `var`)**:
	+ Pros:
		- Can be faster and more efficient for simple property assignments.
	+ Cons:
		- Creates a cluttered and less readable syntax.

**Other Considerations**

When writing JavaScript code, it's essential to consider the trade-offs between readability, maintainability, and performance. In this case, the benchmark is focused on the performance difference between these two approaches.

**Library Usage**

There are no libraries used in these test cases.

**Special JS Features or Syntax**

None mentioned.

**Alternative Approaches**

Other ways to create objects in JavaScript include:

1. **Constructor Functions**: `function MyClass() { this.property = 'value'; }`
2. **Class Declarations**: `class MyClass { constructor() { this.property = 'value'; } }`
3. **Array.prototype.push()**: `var obj = []; obj.push('value');`

These approaches have different trade-offs in terms of performance, readability, and maintainability.

In summary, the provided benchmark tests two approaches to creating objects in JavaScript: using variables (`var`) versus object literal syntax (`{}`). The choice between these approaches depends on the specific use case, personal preference, and the importance of readability and maintainability.

Related benchmarks:

Object Creation vs Variable (version: 0)

Comparing performance of: object vs var

Created: 6 years ago by: Registered User

Jump to the latest result

object

var

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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