Benchmark: falsey vs false - MeasureThat.net

HTML Preparation code:

<script>
    var lock = false
</script>

Tests:

falsey
if (!lock) {}
false
if (lock === false) {}

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
falsey
false

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

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

**What is tested:**

The provided JSON represents a JavaScript microbenchmark that tests the performance of two different approaches for checking if a variable is `falsey` or not. Specifically, it compares:

1. **Non-equality check (`!=`) with boolean value**: `if (!lock) {}`
2. **Equality check with falsiness value**: `if (lock === false) {}`

**Options compared:**

The benchmark compares the performance of these two approaches because they have different execution patterns and can potentially impact performance. The non-equality check is generally faster for primitive values like `false`, while the equality check might be slower due to the overhead of comparing a value with a specific falsiness value.

**Pros and Cons of each approach:**

1. **Non-equality check (`!=`) with boolean value**: This approach is often preferred because it's more straightforward and doesn't require specifying the exact falsiness value.
	* Pros:
		+ Easy to read and understand
		+ Less overhead due to comparison
	* Cons:
		+ May be slower for primitive values like `false`
2. **Equality check with falsiness value**: This approach is more explicit about checking if a value is falsy, which can lead to better performance in certain scenarios.
	* Pros:
		+ Can be faster for primitive values like `false`
	* Cons:
		+ Requires specifying the exact falsiness value
		+ May be less readable

**Library and its purpose:**

There are no libraries mentioned in the benchmark definition or test cases. The benchmark only relies on standard JavaScript functionality.

**Special JS feature or syntax:**

None of the provided code uses any special JavaScript features or syntax that would require additional explanation.

**Other alternatives:**

If you wanted to compare other approaches for checking if a variable is falsy, you could consider:

1. **Using `null` and `undefined` instead of `false`:** This approach can be faster because `null` and `undefined` are primitive values, whereas `false` is an object property.
2. **Using `Boolean()` function:** This approach can provide more control over how falsiness is determined, as the `Boolean()` function can handle various types of inputs.

However, these alternatives would require additional modifications to the benchmark definition and test cases.

**Benchmark preparation code:**

The provided script preparation code simply declares a variable `lock` with the value `false`. This ensures that both tests have a consistent starting point.

**Individual test cases:**

Each test case consists of a single benchmark definition and test name. The first test checks if `if (!lock) {}` is executed, while the second test checks if `if (lock === false) {}` is executed. Both tests aim to measure the performance difference between these two approaches.

**Latest benchmark result:**

The latest benchmark results show that Chrome 88 on Desktop/Windows platforms consistently outperforms Edge 88 on the same platform for both test cases. This suggests that the non-equality check approach (`!=`) with boolean value might be faster due to its simplicity and reduced overhead.

Related benchmarks:

falsey vs false (version: 0)

Comparing performance of: falsey vs false

Created: 5 years ago by: Guest

Jump to the latest result

falsey

false

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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