Benchmark: length>0 vs !! - MeasureThat.net

Script Preparation code:

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

Tests:

Test1
!!newArr.length
Test2
newArr.length > 0

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Test1
Test2

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0.1 Safari/605.1.15

Browser/OS: Safari 14 on Mac OS X 10.15.6

View result in a separate tab

Test name	Executions per second
Test1	17003374.0 Ops/sec
Test2	17199658.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what's being tested in the provided benchmark.

**Benchmark Definition**

The benchmark is testing two different approaches to check if an array has at least one element:

1. `!!newArr.length` (equivalent to `newArr.length > 0`)
2. `newArr.length > 0`

Both expressions are equivalent and use the double-not operator (`!!`) to convert the result of the comparison to a boolean value.

**Options Compared**

The benchmark is comparing two different options:

1. Using the double-not operator (`!!`) to force a boolean conversion.
2. Without using the double-not operator, relying on the browser's implicit boolean conversion rules.

**Pros and Cons of Each Approach**

1. **Using `!!`**: This approach ensures that the result is always a boolean value, regardless of the browser's implementation. However, it can add unnecessary overhead due to the extra operation.
2. **No `!!`**: This approach relies on the browser's implicit conversion rules, which may vary between browsers. In this case, the benchmark uses Safari 14, but other browsers might behave differently.

**Library Used**

The benchmark doesn't use any external libraries. It only defines two simple expressions using JavaScript.

**Special JS Features or Syntax**

There are no special features or syntax used in this benchmark that require additional explanation.

**Other Considerations**

When running benchmarks like this, it's essential to consider the following:

* Cache effects: If the array is reused across multiple tests, cache effects can impact the results.
* Browser quirks: Different browsers may have varying implementations of boolean conversion rules or other features that affect performance.
* System and hardware variations: The benchmarked environment (e.g., Safari 14 on a Mac) might not represent typical user experiences.

**Alternative Approaches**

If you wanted to test similar expressions in different browsers, you could consider using:

1. **Using `Boolean()`**: Instead of `!!`, use the built-in `Boolean()` function to convert the result to a boolean value.
2. **Using `Number()`**: Compare the length property directly without forcing a conversion.
3. **Testing specific browser features**: If you're interested in exploring browser-specific features, consider testing expressions that take advantage of features like `let` declarations or modern JavaScript methods.

Keep in mind that each approach has its own trade-offs and might require adjustments to the benchmark setup to accurately compare results across different browsers and environments.

Related benchmarks:

length>0 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 2 months ago):