Benchmark: Reflect.get vs indexed access vs dot

Script Preparation code:

window.obj = {
  foo: "bar"
}

Tests:

Reflect.get
Reflect.get(obj, "foo");
Indexed access
obj["foo"];
dot
obj.foo;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Reflect.get
Indexed access
dot

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark compares three different ways to access a property on an object in JavaScript:

1. **Indexed Access**: Using square brackets `[]` to access properties, e.g., `obj["foo"]`.
2. **Dot Notation**: Using dot notation to access properties, e.g., `obj.foo`.
3. **Reflect.get**: Using the `Reflect.get()` function from the Reflect API to access properties, e.g., `Reflect.get(obj, "foo")`.

**Options Compared**

The three options are compared in terms of their performance.

* **Indexed Access (obj[“foo”])**: This method uses square brackets to access properties. It's a common way to access object properties, but its performance can vary depending on the browser and engine.
* **Dot Notation (obj.foo)**: This method uses dot notation to access properties. While it's often preferred for readability, its performance is generally better than indexed access because it avoids the overhead of parsing and executing code within square brackets.
* **Reflect.get (Reflect.get(obj, "foo"))**: This method uses the Reflect API to access properties. It's a relatively new addition to JavaScript and provides a way to access property values in a more flexible and expressive way.

**Pros and Cons**

Here are some pros and cons of each approach:

* **Indexed Access**:
	+ Pros: Fast and widely supported.
	+ Cons: Can be slower than dot notation due to parsing overhead, and may not work as expected in older browsers.
* **Dot Notation**:
	+ Pros: Generally faster and more readable than indexed access, works well in most modern browsers.
	+ Cons: May not work as expected in older browsers, which may not support this syntax.
* **Reflect.get**:
	+ Pros: Flexible and expressive way to access properties, can be faster than dot notation in some cases due to caching and optimization by the Reflect API.
	+ Cons: Relative new addition to JavaScript, not yet widely supported in all browsers, and may require additional setup or configuration.

**Library and Syntax**

The benchmark does not use any libraries other than the built-in JavaScript `Reflect` API. The syntax used is standard JavaScript.

**Special JS Features**

There are no special JavaScript features mentioned in the benchmark definition or test cases. However, it's worth noting that some browsers may optimize or implement certain features differently, which could affect performance.

**Other Alternatives**

If you're looking for alternative ways to access properties in JavaScript, here are a few options:

* **Brackets notation**: Some modern browsers support brackets notation (e.g., `obj["foo"]`), but it's not yet widely supported.
* **Property access via `in` operator**: You can use the `in` operator to check if a property exists and then access it using dot notation or indexed access.

Keep in mind that these alternatives may have different performance characteristics and are not necessarily more efficient than dot notation, indexed access, or Reflect.get.

Related benchmarks:

Reflect.get vs indexed access vs dot (version: 0)

Comparing performance of: Reflect.get vs Indexed access vs dot

Created: 5 years ago by: Guest

Jump to the latest result

Reflect.get

Indexed access

dot

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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