Benchmark: Optional chaining

Script Preparation code:

var node = {
  value: 'value',
  data_type: { value: 'data_type_value' }
}

Tests:

Double ampersand
if (node.data_type && node.data_type.value) {}
Optional chaining
if (node.data_type?.value) {}

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Double ampersand
Optional chaining

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Linux; Android 10; CLT-L29) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.88 Mobile Safari/537.36

Browser/OS: Chrome Mobile 100 on Android

View result in a separate tab

Test name	Executions per second
Double ampersand	1328599.0 Ops/sec
Optional chaining	2919384.8 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition and test cases to explain what's being tested, compared, and the pros and cons of each approach.

**Benchmark Definition JSON**

The provided JSON defines a benchmark for testing the performance of optional chaining in JavaScript. The "Name" field is "Optional chaining", but it's not explicitly mentioned as part of the test case. Instead, the actual test cases are defined under the "Test Cases" section.

**Script Preparation Code**

The script preparation code creates an object `node` with a nested property `data_type` that has its own value:
```javascript
var node = {
  value: 'value',
  data_type: { value: 'data_type_value' }
};
```
This setup allows the test cases to exercise optional chaining.

**Html Preparation Code**

The html preparation code is empty, which means there's no HTML involved in these tests.

**Test Cases**

There are two test cases:

1. **Double ampersand**
```javascript
if (node.data_type && node.data_type.value) {}
```
This test case uses the traditional double-ampersand (`&&`) approach to check if `data_type` exists and has a value. The `&&` operator performs a shallow check, meaning it only checks if both operands are truthy.

Pros:

* Widely supported by older browsers
* Easy to understand

Cons:

* May trigger unnecessary function calls or computations due to the `&&` operator's behavior

2. **Optional chaining**
```javascript
if (node.data_type?.value) {}
```
This test case uses optional chaining (`?.`) to safely access the nested property. The `?.` operator returns `undefined` if the operand is null, undefined, or otherwise falsy.

Pros:

* More efficient than traditional double-ampersand approach
* Reduces unnecessary computations and function calls

Cons:

* Requires modern JavaScript engines that support optional chaining (e.g., ECMAScript 2020+)

**Library**

None of the test cases use any external libraries. The code relies solely on built-in JavaScript features.

**Special JS feature**

The test case uses optional chaining (`?.`), which is a relatively new feature introduced in ECMAScript 2020+. It's not supported by older browsers, so it may affect benchmark results across different environments.

**Other alternatives**

If you wanted to test the performance of other approaches, here are some alternative test cases:

* **Nullish coalescing**
```javascript
if (node.data_type ?? { value: '' }) {}
```
This approach uses nullish coalescing (`??`) to provide a default value when `data_type` is falsy. While it's not as efficient as optional chaining, it might be more compatible with older browsers.

* **Explicit checks**
```javascript
if (node.data_type !== undefined && node.data_type !== null) {
  if (node.data_type.value !== undefined) {}
}
```
This approach uses explicit checks to verify the existence and value of `data_type`. While it's more verbose, it might be preferred for older browsers that don't support optional chaining.

Keep in mind that these alternative approaches may change the performance characteristics of the test cases, so you should consider the specific requirements and constraints of your benchmark.

Related benchmarks:

Optional chaining (version: 0)

Comparing performance of: Double ampersand vs Optional chaining

Created: 4 years ago by: Registered User

Jump to the latest result

Double ampersand

Optional chaining

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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