Benchmark: Comparing destructuring assignment with optional chaining

Tests:

Destructuring assignment
const event = { detail: { someKey: undefined, } } const { someKey } = event.detail || {};
Optional chaining
const event = { detail: { someKey: undefined, } } const someKey = event.detail?.someKey;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Destructuring assignment
Optional chaining

Fastest: N/A

Slowest: N/A

Latest run results:

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

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**Overview of the Benchmark**

The provided benchmark measures the performance difference between two syntaxes: destructuring assignment and optional chaining, both used to access nested properties in objects.

**Benchmark Script Preparation Code Analysis**

Since there is no script preparation code provided, we can infer that the test cases rely on the JavaScript engine's built-in support for these syntaxes. The test cases themselves are designed to demonstrate the performance difference between these two approaches.

**Options Compared**

There are only two options being compared:

1. **Destructuring Assignment**: This syntax uses the syntax `const { someKey } = event.detail` to extract the value of `someKey` from the `event.detail` object.
2. **Optional Chaining**: This syntax uses the syntax `const someKey = event.detail?.someKey;` to access the nested property, providing a default value (`undefined`) if the property is null or undefined.

**Pros and Cons**

- **Destructuring Assignment**:
	+ Pros: Can be more concise and expressive in certain situations.
	+ Cons: May lead to code complexity if not used carefully, as it can make the code harder to read and understand for developers without experience with this syntax.
- **Optional Chaining**:
	+ Pros: Provides a safer alternative when working with potentially null or undefined values, reducing the risk of runtime errors.
	+ Cons: Can be less readable for developers who are not familiar with this syntax.

**Other Considerations**

When using optional chaining (`?.`), it's essential to note that if the expression on one side of the chain is `null` or `undefined`, the entire expression will evaluate to `undefined`. If you need a default value, consider combining it with a nullish coalescing operator (`??`) as in: `const someKey = event.detail?.someKey ?? 'default_value';`.

**Library and Special JS Features**

There is no library used in these test cases. However, the use of optional chaining (`?.`) introduces a special JavaScript feature introduced in ECMAScript 2020.

**Alternative Approaches**

Other alternatives for accessing nested properties include:

- Using the dot notation with null checks: `const someKey = event.detail && event.detail.someKey`
- Using bracket notation with null checks: `const someKey = event['detail']['someKey'] && event['detail']['someKey']`

While these approaches can achieve similar results, they may have performance implications due to the addition of null checks.

**Benchmark Preparation Code**

The provided benchmark preparation code is minimal, and it's likely that the test cases are designed to execute quickly and focus on measuring performance differences between the two syntaxes.

Related benchmarks:

Comparing destructuring assignment with optional chaining (version: 0)

Comparing performance of: Destructuring assignment vs Optional chaining

Created: 4 years ago by: Guest

Jump to the latest result

Destructuring assignment

Optional chaining

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):