Let's dive into the world of JavaScript microbenchmarks and analyze the provided benchmark definition.

Benchmark Definition

The benchmark measures the performance difference between three different ways to access an object property in JavaScript:

1. Destructuring notation ({data: {data1: {data2: {property}} }} = globalData;)
2. Dot notation (var property = globalData.data.data1.data2.property;)
3. Bracket notation (var property = globalData['data']['data1']['data2']['property'];)

Options Compared

The benchmark compares the performance of these three approaches:

• Destructuring notation (using destructuring syntax)
• Dot notation (using dot . to access nested properties)
• Bracket notation (using bracket [ ] to access nested properties)

Pros and Cons

Here's a brief analysis of each approach:

• Destructuring Notation: This approach is concise and expressive, but it may not be supported by older browsers or environments. It also requires the property names to be in an object literal format.
• Dot Notation: This approach is widely supported and easy to read, but it can lead to longer code and more nested expressions. It's also slower than destructuring notation due to the overhead of accessing nested properties through dot notation.
• Bracket Notation: This approach is similar to dot notation but uses bracket notation instead. It's faster than dot notation but may be less readable.

Library and Syntax Considerations

The benchmark doesn't use any external libraries, so it only focuses on JavaScript syntax.

There are no special JS features or syntax mentioned in the benchmark definition.

Other Alternatives

If you're interested in exploring other approaches, here are a few alternatives:

• Using Object.keys() and forEach() to iterate over properties instead of dot notation.
• Using JSON.parse() to parse a JSON string containing nested properties (not tested in this benchmark).
• Using function literals or arrow functions to define small, self-contained expressions (not tested in this benchmark).

Keep in mind that these alternatives might not be relevant to the specific use case of this benchmark.

Benchmark Preparation Code

The script preparation code sets up an object globalData with a nested structure:

var globalData = {
  data: {
    data1: {
      data2: {
        property: "value"
      }
    }
  }
};

This object is used to test the performance of accessing its properties using different notation.

Individual Test Cases

Each test case consists of a single benchmark definition with a different notation:

• Destructuring Notation:

var {data: {data1: {data2: {property}} }} = globalData;

• Dot Notation:

var property = globalData.data.data1.data2.property;

• Bracket Notation:

var property = globalData['data']['data1']['data2']['property'];

These test cases are run multiple times to collect performance data.

Latest Benchmark Result

The benchmark result shows the execution rate per second for each notation on a specific browser (Firefox 118) on a desktop device:

• Destructuring Notation: ExecutionsPerSecond = 82780928.0
• Dot Notation: ExecutionsPerSecond = 676816704.0
• Bracket Notation: ExecutionsPerSecond = 743621824.0

These results indicate that destructuring notation is the fastest, followed by bracket notation, and then dot notation.