Benchmark: Boolean vs !! vs Cast type

Script Preparation code:

var newArr = ['1', '2', '3', '4'];

Tests:

Test1
!!newArr.length === true
Test2
Boolean(newArr.length) === true
Test3
newArr.length == true

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Test1
Test2
Test3

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_3_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/135.2 Mobile/15E148 Safari/605.1.15

Browser/OS: Mobile Safari 18 on iOS 18.3.1

View result in a separate tab

Test name	Executions per second
Test1	307085376.0 Ops/sec
Test2	284810272.0 Ops/sec
Test3	291977344.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

**Overview**

The provided benchmark compares the performance of three different approaches to test whether an array length is true:

1. `!!newArr.length` (Double Notation)
2. `Boolean(newArr.length)` (Using the Boolean Constructor)
3. `newArr.length == true` (Using the Loose Equality Operator)

**Options Compared**

The benchmark compares the performance of these three approaches in terms of execution time per second on a desktop device running Safari 16.

**Pros and Cons of Each Approach**

1. **Double Notation (`!!newArr.length`)**
	* Pros: Simple, concise, and widely supported.
	* Cons: May lead to unexpected behavior if `newArr` is an empty array or `NaN` (Not a Number) value.
2. **Using the Boolean Constructor (`Boolean(newArr.length)` )**
	* Pros: More explicit and predictable than double notation.
	* Cons: Requires creating a new object, which may incur additional overhead.
3. **Loose Equality Operator (`newArr.length == true`)**
	* Pros: Simple and widely supported.
	* Cons: Can lead to unexpected behavior if `newArr` is an empty array or contains non-boolean values.

**Library Used**

None, as this benchmark only involves native JavaScript functionality.

**Special JS Feature/Syntax**

No special JavaScript features or syntax are used in this benchmark. The focus is solely on the performance comparison of these three approaches.

**Other Considerations**

* The benchmark does not account for potential differences in browser behavior or implementation specifics that may affect performance.
* Other factors, such as array length and size distribution, could also impact performance results.

**Alternatives**

In addition to the three approaches compared in this benchmark, other alternatives might include:

1. `newArr.length` without any additional operator (which is equivalent to `!!newArr.length`)
2. Using a custom function or utility that converts an array length to a boolean value
3. Utilizing other comparison operators like `===` or `==` with explicit type coercion

However, the double notation (`!!`) and Boolean constructor (`Boolean()`) approaches are likely the most common and widely used in JavaScript development, making them relevant choices for this benchmark.

Related benchmarks:

Boolean vs !! vs Cast type (version: 0)

Comparing performance of: Test1 vs Test2 vs Test3

Created: 2 years ago by: Guest

Jump to the latest result

Test1

Test2

Test3

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):