Benchmark: Variable assignment from object | traditional vs destructuring

Script Preparation code:

var obj = { a: 1, b: 2, c: 3 }

Tests:

Traditional assignment
var a = obj.a
Destructuring assignment
const { a, ...rest } = obj

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Traditional assignment
Destructuring assignment

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; rv:134.0) Gecko/20100101 Firefox/134.0

Browser/OS: Firefox 134 on Windows

View result in a separate tab

Test name	Executions per second
Traditional assignment	1826711808.0 Ops/sec
Destructuring assignment	16854028.0 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.

**What is being tested?**

The benchmark is comparing two approaches to variable assignment from an object: traditional assignment using `var` and destructuring assignment using destructuring syntax (`{ variable, ... } = obj`). The tests are checking which approach is faster in terms of execution frequency per second (ExecutionsPerSecond).

**Options compared**

There are only two options being compared:

1. **Traditional assignment**: Using the `var` keyword to assign a value to a variable inside an object.
```javascript
var a = obj.a;
```
2. **Destructuring assignment**: Using destructuring syntax to extract values from an object into variables.
```javascript
const { a, ...rest } = obj;
```

**Pros and Cons of each approach**

**Traditional assignment:**

Pros:

* Wide support across older browsers and environments.
* Easy to read and understand.

Cons:

* Can lead to variable hoisting issues (e.g., `var a = obj.a` can be executed before `obj.a` is defined).
* Not as flexible or concise as destructuring syntax.

**Destructuring assignment:**

Pros:

* More concise and expressive than traditional assignment.
* Avoids variable hoisting issues since the variables are extracted from an object.

Cons:

* May not work in older browsers or environments that don't support destructuring syntax.
* Can be less readable for some developers if not used correctly.

**Library and purpose**

There is no explicit library mentioned in the benchmark definition, but it's likely that the `obj` object is a simple JavaScript object created using the `var` keyword.

**Special JS feature or syntax**

The test cases use destructuring syntax (`{ ... } = obj`), which is a relatively modern feature introduced in ECMAScript 2015 (ES6). While most modern browsers and Node.js versions support it, older environments may not. This means that the results might be skewed by browser differences.

**Other alternatives**

If you wanted to test alternative approaches, some possible options could include:

* Using `let` or `const` instead of `var`.
* Using a different object assignment method, like spread syntax (`obj.a = ...`) or the `Object.assign()` method.
* Comparing performance with and without a specific library or framework (e.g., React or Angular).
* Testing performance in different environments, such as Node.js vs. browser-based execution.

Keep in mind that these alternatives would require modifications to the benchmark definition and test cases.

Related benchmarks:

Variable assignment from object | traditional vs destructuring (version: 0)

Comparing performance of: Traditional assignment vs Destructuring assignment

Created: 8 years ago by: Guest

Jump to the latest result

Traditional assignment

Destructuring assignment

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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