Benchmark: Accessing "this" vs accessing a variable

Tests:

Accessing "this"
class TestClass { constructor() { this.currency = 'USD'; } accessThis() { return this.currency; } accessVar(curr) { const currency = curr; return currency; } } const testInstance = new TestClass(); testInstance.accessThis();
Accessing variable
class TestClass { constructor() { this.currency = 'USD'; } accessThis() { return this.currency; } accessVar(curr) { const currency = curr; return currency; } } const testInstance = new TestClass(); testInstance.accessVar('USD');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Accessing "this"
Accessing variable

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/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Windows

View result in a separate tab

Test name	Executions per second
Accessing "this"	845160.2 Ops/sec
Accessing variable	931258.7 Ops/sec

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 its test cases.

**Benchmark Definition**

The benchmark definition is a simple JavaScript class `TestClass` with two methods: `accessThis()` and `accessVar()`. The constructor initializes an instance variable `currency` set to `'USD'`. Both methods return different results based on how they access this variable.

**Test Cases**

There are two test cases:

1. **Accessing "this"`**: This test case calls the `accessThis()` method, which returns the value of the `currency` instance variable.
2. **Accessing variable**: This test case calls the `accessVar()` method with a hardcoded string argument `'USD'`. The returned value is stored in a local variable `curr`.

**Options Compared**

The benchmark compares two approaches:

1. Accessing the `currency` instance variable directly using the dot notation (`this.currency`).
2. Accessing the same variable by assigning it to a local variable and then returning its value.

**Pros and Cons**

Here are some pros and cons of each approach:

* **Accessing "this"` (dot notation):
	+ Pros: More efficient, as it avoids creating an additional variable.
	+ Cons: May be less readable for developers who aren't familiar with the `this` keyword.
* **Accessing variable** (assigning to local variable and returning):
	+ Pros: More readable, as it explicitly defines a local variable and its purpose.
	+ Cons: Less efficient due to the creation of an additional variable.

**Library**

There is no explicit library used in this benchmark. However, the `executionsPerSecond` metric suggests that the benchmark might be running inside a browser's JavaScript engine, which provides various APIs and optimizations for performance measurement.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax explicitly used in this benchmark.

**Other Considerations**

When writing performance benchmarks like this one, consider the following:

* Keep your test cases simple and focused on specific scenarios.
* Use meaningful names and comments to explain the purpose of each test case.
* Ensure that your benchmark is representative of real-world usage patterns.
* Use modern JavaScript features and syntax if they are relevant to the scenario being tested.

**Alternatives**

If you're looking for alternative approaches or ways to optimize this benchmark, consider:

* Using a profiler like Chrome DevTools or Node.js Inspector to analyze performance bottlenecks.
* Optimizing the `accessVar()` method by using a more efficient way to access the `currency` variable.
* Adding additional test cases to cover different scenarios, such as accessing the `currency` variable from within another function.

Related benchmarks:

Accessing "this" vs accessing a variable (version: 0)

Comparing performance of: Accessing "this" vs Accessing variable

Created: 2 years ago by: Guest

Jump to the latest result

Accessing "this"

Accessing variable

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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