Benchmark: const vs direct usages

Script Preparation code:

var someObj = {foo: true};

Tests:

direct usage
return someObj.foo;
const assignment
const foo = someObj.foo; return foo;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
direct usage
const assignment

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this JavaScript microbenchmark.

**Benchmark Definition**

The benchmark is testing two different approaches to accessing the `foo` property of an object:

1. **Direct Usage**: This approach uses the dot notation (`someObj.foo`) to access the property directly.
2. **Const Assignment**: This approach assigns the value of `someObj.foo` to a constant variable `foo`, and then returns the value of `foo`.

**Options Compared**

The benchmark is comparing two options:

1. Direct usage (dot notation)
2. Const assignment with variable binding

**Pros and Cons**

* **Direct Usage (Dot Notation)**:
	+ Pros: Simple, intuitive, and widely supported.
	+ Cons: May incur overhead due to the need for dynamic property resolution, which can lead to slower performance in some cases.
* **Const Assignment**: 
	+ Pros: Can be faster because it avoids dynamic property resolution. It also allows the compiler to optimize the assignment more aggressively.
	+ Cons: Requires a temporary variable allocation and binding, which may incur additional overhead.

**Other Considerations**

The benchmark does not consider other factors that might affect performance, such as:

* The size of the object being accessed (e.g., larger objects may require more memory allocations or slower property resolution)
* The type of object being used (e.g., primitive values vs. objects with nested properties)
* Optimizations enabled in the JavaScript engine or runtime environment

**Libraries and Special JS Features**

There are no libraries mentioned in the benchmark definition, but it's worth noting that some JavaScript engines have built-in optimizations or special handling for certain use cases.

* The `const` keyword is a standard feature of modern JavaScript (ES6+), which allows for constant variable declarations.
* Variable binding and temporary variable allocation are also standard features of modern JavaScript.

**Alternative Approaches**

Some alternative approaches to accessing properties in objects include:

1. **Bracket Notation**: Instead of dot notation, you can use bracket notation (`someObj['foo']`) to access properties with non-standard names or using dynamic property names.
2. **Property Access with Object.prototype.hasOwnProperty.call()**: You can use `Object.prototype.hasOwnProperty.call()` to check if a property exists before accessing it.
3. **Using a Function or Closure**: You can create a function or closure that encapsulates the property access logic to improve performance.

Keep in mind that these alternatives may not be relevant to this specific benchmark, and their performance implications might vary depending on the context.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.116 Safari/537.36

Browser/OS: Chrome 80 on Mac OS X 10.15.3

View result in a separate tab

Test name	Executions per second
direct usage	14722523.0 Ops/sec
const assignment	14931603.0 Ops/sec

Related benchmarks:

const vs direct usages (version: 2)

Comparing performance of: direct usage vs const assignment

Created: 4 years ago by: Registered User

Jump to the latest result

direct usage

const assignment

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):