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

Script Preparation code:

var arr = [];

Tests:

array length
if (arr.length) { console.log(1); } else { console.log(0); }
array length > 0
if (arr.length > 0) { console.log(1); } else { console.log(0); }
array.length !== 0
if (arr.length !== 0) { console.log(1); } else { console.log(0); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON and explain what is being tested, the options compared, their pros and cons, and other considerations.

**Benchmark Definition**

The benchmark definition represents three different scenarios for testing the execution speed of JavaScript code related to array length checks:

1. `array.length`: This checks if an empty array has a non-zero length.
2. `array.length > 0`: This checks if an array has at least one element.
3. `array.length !== 0`: This checks if an array has at least one element and is not empty.

**Script Preparation Code**

The script preparation code creates an empty array `arr` before each test case:
```javascript
var arr = [];
```
This ensures that all three test cases start with the same initial state, making the comparison of their execution speeds more meaningful.

**Html Preparation Code**

There is no HTML preparation code provided, which means that the benchmarking process does not involve any complex DOM manipulation or rendering.

**Library Used: None**

None of the test cases use a JavaScript library. This makes it easier to compare the results directly without any potential interference from external dependencies.

**Special JS Features/Syntax: None**

There are no special JavaScript features or syntax used in these test cases, such as async/await, promises, or experimental features.

**Other Alternatives**

If you were to rewrite this benchmark using a different approach, some alternatives could be:

1. Using `Object.keys(arr).length` instead of `arr.length`, which would avoid the issue of `undefined` arrays having zero length.
2. Adding a larger array size before each test case and measuring the execution time of the code that checks for non-zero length.
3. Using a different data structure, such as a linked list or a tree, to make the benchmarking more interesting.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

1. `array.length`:
	* Pros: Simple and straightforward test case.
	* Cons: May not accurately represent real-world scenarios where arrays are often initialized with non-zero lengths.
2. `array.length > 0`:
	* Pros: More realistic representation of common array checks in JavaScript code.
	* Cons: Can be slower than the first option due to the addition of a conditional statement.
3. `array.length !== 0`:
	* Pros: Provides an additional layer of protection against null or undefined arrays.
	* Cons: May require more complex implementation and testing.

**Benchmark Results**

The latest benchmark results show that:

1. `array length > 0` is the fastest, with an average execution time of approximately 129 million executions per second.
2. `array.length !== 0` is slower than both of the above options, but still relatively fast, with an average execution time of around 120 million executions per second.

Keep in mind that these results may vary depending on your specific use case and JavaScript environment.

Latest run results:

Run details: (Test run date: 14 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Windows

View result in a separate tab

Test name	Executions per second
array length	253065.7 Ops/sec
array length > 0	261164.5 Ops/sec
array.length !== 0	259865.5 Ops/sec

Related benchmarks:

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

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

Created: 9 months ago by: Guest

Jump to the latest result

array length

array length > 0

array.length !== 0

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):