Benchmark: globals vs. upvalues

HTML Preparation code:

<script>
'use strict';

const l = (function() {
  'use strict';
  const localObj = {x : 0};
  return function() {
    ++localObj.x;
  };
})();

Function(`return this`)().globalObj = {x : 0};

const g = function() {
  'use strict';
  ++globalObj.x;
};

Object.defineProperty(
	Function(`return this`)(),
	`globalObj2`,
	{value : {x : 0}, __proto__ : null,});

const g2 = function() {
  'use strict';
  ++globalObj2.x;
};
  
</script>

Tests:

g
g();
g2
g2();
l
l();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
g
g2
l

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark tests two approaches to accessing variables in JavaScript:

1. **Using globals**: The `g` function modifies a global variable `globalObj.x`.
2. **Using upvalues**: The `l` function uses an immediately invoked function expression (IIFE) with a closure to access and modify a local object `localObj.x`.

**Options Compared**

The benchmark compares the performance of these two approaches:

* Using globals (`g()`)
* Using upvalues (`l()`)

**Pros and Cons**

1. **Using Globals**
	* Pros:
		+ Simple and easy to understand
	* Cons:
		+ Can lead to naming conflicts and pollution in global scope
		+ May not be suitable for large-scale applications or libraries due to potential performance issues
2. **Using Upvalues**
	* Pros:
		+ Encourages encapsulation and separation of concerns
		+ Reduces polluting the global scope
		+ Can improve performance by reducing object lookups
	* Cons:
		+ May be more complex for developers to understand, especially for those new to JavaScript or closures
		+ Requires careful management of upvalues to avoid memory leaks

**Library**

The benchmark uses none, but it's worth noting that the `Function` constructor is used to create functions with a specific behavior. The `Object.defineProperty` method is also used to define properties on an object.

**Special JavaScript Feature/Syntax**

This benchmark doesn't explicitly use any special features or syntax. However, it does utilize closures and the `this` keyword in a non-traditional way, which can be confusing for some developers.

**Other Alternatives**

Other approaches to accessing variables in JavaScript could include:

1. **Module exports**: Using ES6 modules to export and import variables.
2. **Class-based encapsulation**: Using classes to encapsulate data and behavior.
3. **Function scope**: Using the `let` or `const` keywords with block scopes to manage variable access.

Keep in mind that each approach has its pros and cons, and the choice of which one to use depends on the specific requirements of your project or application.

In this benchmark, using upvalues (`l()`) appears to be slightly faster than using globals (`g()`). However, the actual performance difference may not be significant, and other factors such as developer maintainability and understanding should also be considered when deciding between these approaches.

Latest run results:

Run details: (Test run date: 2025 years ago)

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:56.0) Gecko/20100101 Firefox/56.0.1 Waterfox/56.0.1

Browser/OS: Firefox 56 on Windows 7

View result in a separate tab

Test name	Executions per second
g	370164192.0 Ops/sec
g2	324959552.0 Ops/sec
l	221739440.0 Ops/sec

Related benchmarks:

globals vs. upvalues (version: 5)

Comparing performance of: g vs g2 vs l

Created: 6 years ago by: Registered User

Jump to the latest result

g

g2

l

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):