Benchmark: Destructuring vs Dot notation

Tests:

Destructuring
const things = [{name: 'Alan', swearing: 'Mid'}, {name: 'Jason', swearing: 'High'}, {name: 'Stuart', swearing: 'Low'}] const [{swearing}] = things
Dot notation
const things = [{name: 'Alan', swearing: 'Mid'}, {name: 'Jason', swearing: 'High'}, {name: 'Stuart', swearing: 'Low'}] const level = things[0].swearing

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Destructuring
Dot notation

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/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Windows

View result in a separate tab

Test name	Executions per second
Destructuring	76656496.0 Ops/sec
Dot notation	104789696.0 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 explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark definition is a simple JSON object that outlines the benchmark's purpose:

* `Name`: The name of the benchmark, which is "Destructuring vs Dot notation".
* `Description`: No description is provided for this benchmark.
* `Script Preparation Code` and `Html Preparation Code`: These fields are empty, indicating that no custom code needs to be written before running the benchmark.

**Individual Test Cases**

There are two test cases:

1. **Destructuring**
	* The benchmark definition contains a JavaScript snippet that assigns values from an array of objects using destructuring syntax (`const [{swearing}] = things;`).
2. **Dot notation**
	* The benchmark definition contains a similar JavaScript snippet, but this time uses dot notation to access the `swearing` property (`const level = things[0].swearing;`).

**What's being tested**

The two test cases are designed to compare the performance of destructuring vs dot notation in accessing array elements. Specifically:

* The benchmark is testing how fast it can execute each syntax to extract a value from an array of objects.
* The order of operations (accessing the `swearing` property) is the same for both tests, but the syntax used differs.

**Pros and Cons**

### Destructuring

Pros:

* Can be more concise and readable in many cases
* Less error-prone than dot notation, as it's harder to accidentally access an object with a different key

Cons:

* May incur additional overhead due to the need to parse and compile the destructured expression
* Requires modern JavaScript versions that support array destructuring (ECMAScript 2018+)

### Dot Notation

Pros:

* Widely supported across older browsers and platforms
* Easier to debug, as it's harder to get wrong
* Faster execution time due to its simpler parsing and compilation requirements

Cons:

* Can be less concise and more error-prone than destructuring syntax
* May lead to "property chaining" issues if not used carefully (e.g., accessing `things[0].swearing` instead of just `things[0].swearing`)

**Library/Feature Usage**

In the benchmark, no external libraries or special features are explicitly mentioned. However, it's worth noting that modern JavaScript engines might use various optimizations and inlining techniques that could affect performance.

**Other Alternatives**

If you're interested in exploring other approaches for comparing performance, consider these alternatives:

* **String interpolation**: Instead of using destructuring or dot notation, try accessing the `swearing` property using string interpolation (`const level = 'High'; if (things[0].name === 'Alan') {level = things[0].swearing;}`)
* **Object literal creation**: Create an object literal with a single property and access it using dot notation (`const obj = { swearing: 'High' }; const level = obj.swearing`)
* **Arrays of objects vs nested arrays**: Test how performance compares when accessing nested array elements versus using flat arrays

These alternatives will help you better understand the nuances of JavaScript performance optimization and explore different strategies for testing.

In conclusion, the provided benchmark is a great example of how to test performance differences between two syntaxes in modern JavaScript. By understanding the pros and cons of each approach, you can gain valuable insights into the trade-offs involved when optimizing JavaScript code for performance.

Related benchmarks:

Destructuring vs Dot notation (version: 0)

Comparing performance of: Destructuring vs Dot notation

Created: 3 years ago by: Guest

Jump to the latest result

Destructuring

Dot notation

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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