Benchmark: Boolean vs !! - MeasureThat.net

Script Preparation code:

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

Tests:

Test1
!!newArr.length
Test2
Boolean(newArr.length)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Test1
Test2

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data for MeasureThat.net, a website that allows users to create and run JavaScript microbenchmarks.

**Benchmark Definition**

The benchmark definition is provided in two parts:

1. **Script Preparation Code**: This section defines an array `newArr` containing four string elements: `'1'`, `'2'`, `'3'`, and `'4'`. This code is executed before each test case.
2. **Html Preparation Code**: There is no HTML preparation code provided, which means that the benchmark only runs in a headless environment, without displaying any UI.

**Individual Test Cases**

There are two individual test cases:

1. `!!newArr.length`: This test case measures the performance of the double-bang operator (`!!`) used with the length property of the array `newArr`. The `!!` operator is a shorthand for `Boolean(value)`, where `value` is evaluated as a boolean.
2. `Boolean(newArr.length)`: This test case measures the performance of the `Boolean()` function applied to the length property of the array `newArr`.

**Options Compared**

The two test cases compare the performance of using the double-bang operator (`!!`) versus the explicit `Boolean()` function with the `length` property.

**Pros and Cons**

1. **Double-Bang Operator (`!!`)**:
	* Pros: concise, readable, and often faster than explicit `Boolean()`.
	* Cons: may be less intuitive for developers who are not familiar with this syntax.
2. **Explicit `Boolean()`**:
	* Pros: clear and easy to understand, especially for developers who are new to JavaScript.
	* Cons: may be slightly slower due to the additional function call.

**Library**

There is no library used in these test cases.

**Special JS Feature/Syntax**

The double-bang operator (`!!`) is a shorthand syntax for `Boolean(value)`. It was introduced in ECMAScript 2008 and has since become a common idiom in JavaScript.

**Other Alternatives**

If you want to compare the performance of other ways to evaluate an expression, you could consider adding additional test cases:

* Using `new Boolean(expression)` (explicit boolean constructor)
* Using `true`/`false` directly (e.g., `if (expression)`)
* Using a conditional statement with an empty body (e.g., `if (!expression) { }`)

Keep in mind that the performance impact of these alternatives may be negligible, and MeasureThat.net is primarily focused on comparing the performance of different ways to write the same code.

Latest run results:

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

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 18 on iOS 18.1

View result in a separate tab

Test name	Executions per second
Test1	19325556.0 Ops/sec
Test2	10773682.0 Ops/sec

Related benchmarks:

Boolean vs !! (version: 0)

Comparing performance of: Test1 vs Test2

Created: 3 years ago by: Guest

Jump to the latest result

Test1

Test2

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):