Benchmark: array.length === 0 vs !array.length

Tests:

array.length === 0
const array = []; for (let i = 0; i < 10000; i++) { if (array.length === 0) { // } }
!array.length
const array = []; for (let i = 0; i < 10000; i++) { if (!array.length) { // } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.length === 0
!array.length

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser/OS: Chrome 119 on Windows

View result in a separate tab

Test name	Executions per second
array.length === 0	175013.3 Ops/sec
!array.length	173050.6 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to explain the benchmark test and its variations.

**Benchmark Test Overview**

The provided benchmark test is designed to measure the performance difference between two approaches for checking if an empty array has a length of 0:

1. `array.length === 0`
2. `!array.length`

This test is useful in JavaScript development, as it can help identify potential optimization opportunities or performance bottlenecks.

**Options Compared**

The benchmark tests compare the performance of two options:

1. **`array.length === 0`**: This option uses a direct comparison to check if the array has a length of 0.
2. **`!array.length`**: This option uses the negation operator (`!`) to negate the result of `array.length`, effectively checking if the length is 0.

**Pros and Cons**

Here are some pros and cons of each approach:

* `array.length === 0`:
	+ Pros: Simple, readable, and easy to understand.
	+ Cons: May be slower due to the comparison operation.
* `!array.length`:
	+ Pros: May be faster due to the negation operator being optimized by the JavaScript engine.
	+ Cons: Less intuitive and may require more explanation to understand.

**Library Usage**

The test code does not use any external libraries. It only relies on built-in JavaScript features.

**Special JS Features or Syntax**

There is no special JavaScript feature or syntax used in this benchmark test.

**Other Alternatives**

If the `!array.length` approach is too hard to read, another alternative could be:

* `array.length > 0`: This option checks if the array has a length greater than 0. While it may seem similar to `!array.length`, it's not exactly equivalent, as an empty string would still have a length of 0.

However, using `array.length > 0` is generally considered less efficient and less readable than `!array.length`.

In summary, the benchmark test is designed to measure the performance difference between two approaches for checking if an empty array has a length of 0. The `!array.length` approach may be faster due to optimization by the JavaScript engine, but it's less intuitive and requires more explanation.

Related benchmarks:

array.length === 0 vs !array.length (version: 0)

Comparing performance of: array.length === 0 vs !array.length

Created: one year ago by: Guest

Jump to the latest result

array.length === 0

!array.length

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):