Benchmark: filter Boolean vs !!

Script Preparation code:

var elements = [0, 1, false, 2, '', 3, undefined, 'abc', 'de'];

Tests:

!!
elements.filter((e) => !!e)
Boolean
elements.filter(Boolean)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
!!
Boolean

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

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Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is being tested?**

The provided JSON represents two benchmark test cases:

1. `filter Boolean vs !!`: This test compares the performance of using the `Boolean()` function versus the double-bang operator (`!!`) in a filter method.
2. The individual test cases:
	* `"elements.filter((e) => !!e)"` (using `!!`): This test case filters an array of elements using the double-bang operator.
	* `"elements.filter(Boolean)"` (using `Boolean()`: This test case filters an array of elements using the built-in `Boolean()` function.

**Options being compared**

The two approaches being compared are:

1. **Double-bang operator (`!!`)**: A shorthand for converting a value to a boolean, where `true` becomes 1 and `false` becomes 0. In the context of filtering an array, this means that non-boolean values will be converted to booleans.
2. **Built-in `Boolean()` function**: This function explicitly converts its input to a boolean value.

**Pros and cons**

* Double-bang operator (`!!`):
	+ Pros:
		- Concise syntax
		- Can be faster since it's a single operation (evaluation of the expression)
	+ Cons:
		- May introduce subtle bugs if not understood correctly
		- Not explicitly converting to boolean, but rather evaluating the expression as a whole
* Built-in `Boolean()` function:
	+ Pros:
		- Explicitly converts input to boolean
		- More readable and maintainable code
	+ Cons:
		- May be slower since it's an additional step (function call)
		- Longer syntax

**Library usage**

There is no explicit library mentioned in the provided JSON. However, if we look at the test cases, we can infer that the `filter()` method is being used, which is a native JavaScript method.

**Special JS features or syntax**

The double-bang operator (`!!`) is a special feature in JavaScript, but it's not explicitly mentioned as a special feature in this benchmark. However, it's worth noting that `!!` can have unexpected behavior with certain types of values (e.g., objects, arrays).

**Other alternatives**

If you were to implement this benchmark yourself, here are some alternative approaches:

1. **Using a boolean value directly**: Instead of using the double-bang operator or the built-in `Boolean()` function, you could simply use a boolean value in the filter method.
2. **Using an arrow function with explicit type conversion**: You could use an arrow function with explicit type conversion to convert non-boolean values to booleans.

Here's some example code for each alternative:
```javascript
// Using a boolean value directly
elements.filter(value => typeof value === 'boolean');

// Using an arrow function with explicit type conversion
elements.filter((value) => {
  return Boolean(value);
});
```
Keep in mind that these alternatives may not be as concise or readable as the double-bang operator or the built-in `Boolean()` function.

I hope this explanation helps!

Related benchmarks:

filter Boolean vs !! (version: 0)

Comparing performance of: !! vs Boolean

Created: 2 years ago by: Guest

Jump to the latest result

!!

Boolean

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):