Benchmark: -1 vs ~ - MeasureThat.net

Tests:

~== -1
var test = 'hello'; var newData; if (test.indexOf('he') !== -1) { newData = test; }
!~
var test = 'hello'; var newData; if (!~test.indexOf('he')) { newData = test; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
~== -1
!~

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36

Browser/OS: Chrome 80 on Mac OS X 10.13.6

View result in a separate tab

Test name	Executions per second
~== -1	1371972352.0 Ops/sec
!~	1383715456.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The provided JSON represents two individual test cases for a JavaScript microbenchmark on MeasureThat.net. The goal is to compare the performance of two different approaches: `~== -1` and `!~`.

**Approach 1: ~== -1**

In this approach, a string variable `test` is initialized with the value `'hello'`. Then, an `if` statement checks if the index of `'he'` in `test` is not equal to `-1`, which means `'he'` is found within the string. If true, another variable `newData` is assigned the same value as `test`.

This approach can be seen as a more traditional way of checking if a substring exists within a larger string. It explicitly checks for the presence of the substring and assigns a value to `newData` only if it's found.

**Approach 2: !~**

In this approach, the `!~` operator is used, which is a bitwise NOT operator applied to the result of `test.indexOf('he')`. This operator returns `-1` if the index is not found, and a value greater than `-1` otherwise. The `!` operator then negates this result.

This approach can be seen as a more concise way of checking for the absence of a substring within a larger string. It uses a single operation to negate the original result, which might be faster in terms of CPU cycles.

**Pros and Cons**

Approach 1 (`~== -1`):

Pros:

* More explicit and readable code
* Easier to understand the intent of the code

Cons:

* Might require more CPU cycles due to the explicit comparison
* Could lead to slower performance if the string is very large

Approach 2 (`!~`):

Pros:

* Concise and compact code
* Can be faster in terms of CPU cycles due to the single operation

Cons:

* Less readable code, might be harder to understand for others or for yourself after a while
* Might not perform well if the string is very large, as it relies on a bitwise operation that can lead to branch prediction errors.

**Other Considerations**

The `~== -1` approach uses a simple substring search with an explicit comparison. The `!~` approach uses a bitwise NOT operator to negate the result of the `indexOf()` method.

Both approaches have their trade-offs, and the best choice depends on the specific use case and performance requirements.

**Alternative Approaches**

Other alternatives that might be considered include:

* Using regular expressions (e.g., `test.indexOf('he') === -1`)
* Using a more modern JavaScript feature like `includes()`
* Optimizing the string comparison using techniques like caching or memoization

However, these alternative approaches are not explicitly mentioned in the provided benchmark results and would require additional analysis to determine their performance characteristics.

Related benchmarks:

-1 vs ~ (version: 0)

Something

Comparing performance of: ~== -1 vs !~

Created: 4 years ago by: Guest

Jump to the latest result

~== -1

!~

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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