Benchmark: If vs or equality check and re-assignment

Script Preparation code:

var jsonObject = {};

for (let i = 0; i < 500; i++) {
  const key = `key_${i}`;
  const value = Math.random() + 1; // You can replace this with any desired value.
  jsonObject[key] = value;
}

Tests:

if re-assignment
if (!jsonObject['key-250']) { jsonObject['key-250'] = 0 }
Or re-assignment
jsonObject['key-250'] = jsonObject['key-250'] || 0

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
if re-assignment
Or re-assignment

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36

Browser/OS: Chrome 116 on Linux

View result in a separate tab

Test name	Executions per second
if re-assignment	5007923.5 Ops/sec
Or re-assignment	4826373.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the provided JSON benchmark data.

**Benchmark Definition**

The benchmark is designed to measure the performance difference between two approaches:

1. **If Statement with Re-Assignment**: This approach uses an if statement to check if a key exists in the `jsonObject`. If it doesn't exist, it reassigns the value of that key.
2. **Or Operator with Re-Assignment**: This approach uses the OR operator (`||`) to achieve the same result as the if statement. It also reassigns the value of the key if it doesn't exist.

**Options Compared**

The benchmark is comparing two options:

* **If Statement with Re-Assignment**: `if (!jsonObject['key-250']) { jsonObject['key-250'] = 0; }`
* **Or Operator with Re-assignment**: `jsonObject['key-250'] = jsonObject['key-250'] || 0`

**Pros and Cons**

1. **If Statement with Re-Assignment**:
	* Pros: More readable and maintainable code, easier to understand the logic.
	* Cons: Can lead to slower performance due to the re-assignment of the key value.
2. **Or Operator with Re-assignment**:
	* Pros: Faster performance, as it avoids the re-assignment of the key value. However, it may require more lines of code and is less readable.
	* Cons: Less maintainable and understandable code.

**Library and Special JS Feature**

There is no library or special JavaScript feature used in this benchmark. The script only uses standard JavaScript syntax.

**Considerations**

When writing performance-critical code, consider the following:

* Use const declarations whenever possible to avoid reassignments.
* Avoid using OR operators with re-assignments if possible.
* Use conditional statements (if/else) for more readable and maintainable code.

**Other Alternatives**

If you're looking for alternative approaches, here are a few options:

1. **Use `in` operator**: Instead of checking if a key exists using `jsonObject['key-250']`, use the `in` operator (`'key-250' in jsonObject`). This is faster and more readable.
2. **Use `??` operator**: Introduce the nullish coalescing operator (`??`) to simplify the re-assignment logic.

```javascript
jsonObject['key-250'] = jsonObject['key-250'] ?? 0;
```

This approach eliminates the need for an if statement and is more readable than using the OR operator.

Related benchmarks:

If vs or equality check and re-assignment (version: 0)

Comparing performance of: if re-assignment vs Or re-assignment

Created: one year ago by: Registered User

Jump to the latest result

if re-assignment

Or re-assignment

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):