Benchmark: array.length 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); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

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

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:125.0) Gecko/20100101 Firefox/125.0

Browser/OS: Firefox 125 on Windows

View result in a separate tab

Test name	Executions per second
array.length	233232.9 Ops/sec
array.length === 0	240252.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Measuring the performance of JavaScript microbenchmarks can be a fascinating topic.

**Benchmark Definition and Purpose**

The provided JSON represents a benchmark definition, which is a script that defines two test cases: `array.length` and `array.length === 0`. The purpose of this benchmark is to measure the execution time difference between these two tests.

**Script Preparation Code**

The script preparation code `var arr = [];` creates an empty JavaScript array. This line of code is executed only once before running each test case, ensuring that both test cases start with the same state (an empty array).

**Html Preparation Code**

There is no HTML preparation code provided, which means that there are no additional setup or initialization tasks required to run these tests.

**Test Cases and Options Compared**

The two test cases compare the execution time of:

1. `arr.length`: This expression returns the length of the array.
2. `arr.length === 0`: This expression checks if the length of the array is equal to 0.

The key difference between these two expressions is that one evaluates the length of the array, while the other performs a comparison.

**Pros and Cons of Each Approach**

1. `arr.length`:
	* Pros: Faster execution time since it only requires accessing the array's length property.
	* Cons: May be more expensive than `arr.length === 0` due to potential overhead of accessing the array's properties.
2. `arr.length === 0`:
	* Pros: More accurate results, as it checks for both the existence and value of the array length.
	* Cons: Slower execution time since it performs an additional comparison operation.

**Library Used**

There is no explicit library mentioned in the provided JSON. However, it's likely that the benchmark uses the built-in `Array` object and its properties.

**Special JS Feature or Syntax**

Neither of the test cases uses any special JavaScript features or syntax.

**Other Considerations**

To accurately measure the execution time difference between these two tests, it's essential to ensure that:

* The array is initialized in a consistent state (e.g., empty) before running each test case.
* Both test cases use the same environment and configuration.
* The benchmark is run on a stable and controlled platform.

**Alternative Benchmarks**

If you're interested in exploring other JavaScript benchmarks, consider checking out:

1. **Bench.js**: A popular benchmarking library for Node.js and browser-side JavaScript.
2. **Benchmark.js**: Another widely used benchmarking library for JavaScript.
3. **jsperf**: An online benchmarking platform that allows users to create and compare benchmarks.

These resources provide a more comprehensive understanding of the performance characteristics of various JavaScript operations, including array-related tasks.

Related benchmarks:

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

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

Created: 2 years ago by: Guest

Jump to the latest result

array.length

array.length === 0

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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