Benchmark: optional chaining vs. non-optional chaining

Script Preparation code:

var job = {
  "summary": {
    "total_actions": 4,
    "finished_actions": 4
  },
  "updated_at": "2020-07-15T10:24:42.364000000Z",
  "job_id": "4b1733e7-c8e0-4fdd-a7f1-13d3ab725c92",
  "description": "Job from our export",
  "created_at": "2020-07-15T10:24:40.975000000Z",
  "status": "finished",
  "tags": {
    "export_id": [
      "8848c5d8-fd44-43c0-b7f2-1428d0f4891a" 
    ]
  }
}

Tests:

Without optional chaining
if (job.tags.export_id) { // do nothing }
optional chaining (?.) once
if (job.tags?.export_id) { // do nothing }
optional chaining (?.) two levels
if (job?.tags?.export_id) { // do nothing }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Without optional chaining
optional chaining (?.) once
optional chaining (?.) two levels

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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Windows

View result in a separate tab

Test name	Executions per second
Without optional chaining	23771608.0 Ops/sec
optional chaining (?.) once	23529680.0 Ops/sec
optional chaining (?.) two levels	23476628.0 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 is being tested, compared, and their pros and cons.

**Benchmark Description**

The benchmark compares the performance cost of using optional chaining (`?.`) when not required in JavaScript compared to traditional if-conditional statements (e.g., `if (job.tags.export_id)`).

**Test Cases**

There are three test cases:

1. **Without optional chaining**
	* Benchmark Definition: `if (job.tags.export_id) { // do nothing }`
	* Purpose: This test case checks the performance of a traditional if-conditional statement without using optional chaining.
2. **Optional chaining once**
	* Benchmark Definition: `if (job.tags?.export_id) { // do nothing }`
	* Purpose: This test case checks the performance of optional chaining when used only once (`?.`).
3. **Optional chaining two levels**
	* Benchmark Definition: `if (job?.tags?.export_id) { // do nothing }`
	* Purpose: This test case checks the performance of optional chaining when used twice (`?.`).

**Performance Comparison**

The benchmark measures the execution time for each test case using a browser's JavaScript engine. The results are likely comparing the performance cost of these two approaches:

1. **Traditional if-conditional statement**: The engine needs to evaluate the `job.tags.export_id` expression and decide whether it exists or not, which involves checking the type and value of the property.
2. **Optional chaining (`?.`)**: This syntax allows for a more concise way to check if an object has a specific property without explicitly declaring its existence.

**Pros and Cons**

1. **Traditional if-conditional statement**
	* Pros:
		+ Can be more readable and maintainable for complex logic.
		+ Does not require any additional syntax or features.
	* Cons:
		+ May incur higher performance costs due to the extra evaluation steps.
2. **Optional chaining (`?.`)**
	* Pros:
		+ More concise and expressive, reducing code duplication.
		+ Can improve readability and maintainability for simple logic.
	* Cons:
		+ Requires a specific syntax and understanding of optional chaining.
		+ May not be supported by all JavaScript engines or older versions.

**Library/Feature Usage**

In the provided benchmark, no libraries are explicitly mentioned. However, the use of optional chaining (`?.`) is a feature introduced in ECMAScript 2020 (ES10) and has been widely adopted in modern JavaScript development.

**Other Alternatives**

If you prefer to avoid optional chaining or if it's not supported by your target environment, alternative approaches can be used:

1. **Traditional if-conditional statement**: As mentioned earlier, this approach requires explicit checking for property existence.
2. **Using the `in` operator**: `if ('export_id' in job.tags)` can achieve similar results to optional chaining but with a slightly different syntax.

Keep in mind that these alternatives may have varying performance characteristics and code readability implications compared to using optional chaining (`?.`).

Related benchmarks:

optional chaining vs. non-optional chaining (version: 0)

Determine performance cost of using optional chaining when not required

Comparing performance of: Without optional chaining vs optional chaining (?.) once vs optional chaining (?.) two levels

Created: 2 years ago by: Registered User

Jump to the latest result

Without optional chaining

optional chaining (?.) once

optional chaining (?.) two levels

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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