Benchmark: && or !== undefined

Tests:

&&
const rule = { thing: true, } if (rule && rule.thing) { }
!== undefined
const rule = { thing: true, } if (rule !== undefined && rule.thing) { }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
&&
!== undefined

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what is being tested.

**Benchmark Definition**
The benchmark definition is a simple JavaScript statement that checks if two conditions are met:
1. `rule && rule.thing`
2. `rule !== undefined && rule.thing`

In essence, both tests are checking if `rule` is not null or undefined and has a property called `thing`. However, they differ in how the `undefined` check is performed.

**Options Compared**
The options being compared are:

1. `&&` (and)
2. `!== undefined` (not equal to undefined)

These two operators have different behavior when applied to the `rule` object.

**Pros and Cons**

### Using `&&`

* **Pros:**
	+ More concise and readable code
	+ Faster execution (since it's a shorter expression)
* **Cons:**
	+ If `rule` is truthy, it will still execute even if `thing` is falsy
	+ Less explicit about the intention of checking for both conditions

### Using `!== undefined`

* **Pros:**
	+ More explicit about checking for both null/undefined and presence of `thing`
	+ Will not execute if either condition is false
* **Cons:**
	+ Longer code
	+ Possible performance impact due to additional checks

**Library Usage**
There are no libraries explicitly mentioned in the benchmark definition.

**Special JS Features or Syntax**
None. The syntax used is standard JavaScript.

**Alternative Approaches**

1. Using `&&` with a default value:
```javascript
if (rule && rule.thing || {}) {
  // code to execute
}
```
This approach combines the benefits of both operators while avoiding potential issues with falsy values.

2. Using `?.` optional chaining operator (available in modern JavaScript):
```javascript
if (rule?.thing) {
  // code to execute
}
```
This approach provides a more concise and readable way to check for presence of `thing` without the need for explicit null checks.

3. Using `===` or `!==` with explicit type checking:
```javascript
if (typeof rule === 'object' && rule !== null && rule.thing) {
  // code to execute
}
```
This approach provides a more explicit and type-safe way to check for the presence of `thing`, but may have performance implications due to additional checks.

The choice of which approach to use depends on personal preference, coding style, and specific requirements of the project.

Related benchmarks:

&& or !== undefined (version: 0)

Comparing performance of: && vs !== undefined

Created: 3 years ago by: Guest

Jump to the latest result

&&

!== undefined

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):