Benchmark: && or !== undefined 2

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:

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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 definition and test cases to understand what is being tested.

**Benchmark Definition:**

The `&&` and `!== undefined` operators are being compared, but not exactly in their traditional form. The operators are used with an object literal `rule` that has a single property `thing` set to `true`. The comparisons are made as follows:

* For the `&&` operator: `if (rule && rule.thing) { ... }`
	+ This checks if both `rule` and `rule.thing` are truthy.
	+ Since `rule.thing` is always true, this simplifies to just checking if `rule` is truthy.
* For the `!== undefined` operator: `if (rule === undefined && rule.thing) { ... }`
	+ This checks if `rule` is equal to `undefined` and also `rule.thing` is truthy.

**What is being tested?**

The benchmark is testing the performance difference between these two comparison approaches:

1. Using the `&&` operator with an object literal.
2. Using the `!== undefined` operator with an object literal.

**Options compared:**

The main option being compared is the order of operations and potential short-circuiting behavior in each case.

* In the `&&` operator, it first checks if `rule` is truthy before checking its properties.
* In the `!== undefined` operator, it first checks if `rule` is equal to `undefined`, which can be expensive for large objects. Then, if that's true, it still needs to check if `rule.thing` is truthy.

**Pros and Cons:**

1. `&&` operator:
	+ Pros:
		- Can potentially short-circuit the evaluation of `rule.thing`.
		- May be faster due to early return.
	+ Cons:
		- Requires both operands to be evaluated, even if only one is necessary.
2. `!== undefined` operator:
	+ Pros:
		- Allows for earlier return if `rule === undefined`, reducing unnecessary computations.
	+ Cons:
		- May introduce additional overhead due to the `=== undefined` check.

**Library and special JS features:**

There are no libraries explicitly mentioned in the benchmark definition. However, JavaScript's object literal syntax is used throughout.

**Special JS feature:**

The use of the `&&` operator with an object literal is a common idiom in JavaScript. It takes advantage of the fact that the `&&` operator has short-circuiting behavior, where it stops evaluating its left operand as soon as it becomes falsy.

**Other alternatives:**

If you were to rewrite these comparisons using more traditional methods, you might consider:

* Using a conditional statement (`if (rule && rule.thing) { ... }`)
* Using the `?.` optional chaining operator (introduced in ECMAScript 2020):
```javascript
if (rule?.thing) {
  // ...
}
```
The `?.` operator allows for safe navigation and avoids potential null or undefined issues.

Keep in mind that these alternatives might not provide the same performance benefits as using the original idioms, but they can make your code more readable and maintainable.

Related benchmarks:

&& or !== undefined 2 (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):