Benchmark: regular vs destruct

HTML Preparation code:

<script> 
const arrayA = [];
for ( let i = 0; i< 1000; ++i){
	arrayA.push({a: 123, b: 'test', c: new Date()});
}
</script>

Tests:

Regular
let r; for (const item of arrayA){ r = item.b; }
Destruct
let r; for (const {b} of arrayA){ r = b; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regular
Destruct

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Description**

The provided benchmark is designed to compare two approaches for iterating over an array and extracting a specific value: using destructuring syntax (`"Destruct"`) versus traditional regular expression assignment (`"Regular"`).

**What is being tested?**

In this benchmark, the test cases are comparing:

1. **Iteration over an array**: The script generates an array `arrayA` with 1000 objects, each containing properties `a`, `b`, and `c`. The test cases then iterate over this array to extract the value of property `b`.
2. **Assignment of extracted values**: After iterating over the array, the benchmark measures how long it takes to assign a variable (`r`) with the extracted value.

**Options compared**

The two options being compared are:

1. **Regular**: Using traditional regular expression assignment (`let r; for (const item of arrayA) { r = item.b; }`)
2. **Destruct**: Using destructuring syntax (`let r; for (const { b } of arrayA) { r = b; }`)

**Pros and Cons**

* **Regular**:
	+ Pros: Easy to understand, straightforward syntax.
	+ Cons: May be slower due to the need for explicit type assignment and property access.
* **Destruct**:
	+ Pros: More concise syntax, potentially faster execution.
	+ Cons: Requires understanding of destructuring syntax, which may not be immediately familiar to all developers.

**Library usage**

The benchmark does not explicitly mention any external libraries. However, it's worth noting that some JavaScript engines, like V8 (used by Chrome), have built-in optimizations for certain patterns and syntax.

**Special JS feature or syntax**

The benchmark uses a modern JavaScript feature: **Destructuring syntax**, which was introduced in ECMAScript 2015 (ES6). This syntax allows for more concise and expressive code when working with objects. Other notable features used here are:

* **Template literals** (`<script>...</script>`): Allow for easy string manipulation and formatting.
* **Type annotations** (e.g., `let r;`): Help the JavaScript engine understand the expected data type of a variable.

**Alternatives**

If you're interested in exploring other microbenchmarking tools or alternatives, here are some popular options:

1. **jsbench**: A lightweight benchmarking tool specifically designed for JavaScript.
2. **Benchmark.js**: A popular benchmarking library that provides a simple and intuitive API.
3. **V8 Benchmark Suite**: A collection of benchmarks created by the V8 team to test various aspects of JavaScript performance.

Keep in mind that each tool has its strengths and weaknesses, and the choice ultimately depends on your specific needs and use cases.

I hope this explanation helps!

Related benchmarks:

regular vs destruct (version: 0)

Comparing performance of: Regular vs Destruct

Created: 4 years ago by: Guest

Jump to the latest result

Regular

Destruct

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):