Benchmark: RegExp replace vs string ops

Tests:

RegExp replace
const strip = (str) => str.replace(/\/?index$/, ''); strip('en/index'); strip('index'); strip('en/guides/getting-started');
String ops
const strip = (str) => str === 'index' ? '' : str.endsWith('/index') ? str.slice(0, -6) : str; strip('en/index'); strip('index'); strip('en/guides/getting-started');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
RegExp replace
String ops

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**What is tested?**

The provided benchmark tests two approaches to remove the last part of a string: using regular expressions (`RegExp replace`) and using basic string operations (`String ops`).

**Options compared**

There are two options being compared:

1. **RegExp Replace**: This approach uses the `replace()` method with a regular expression to remove the last part of the string. The regular expression `/\\/?index$/` matches any character that is escaped (i.e., preceded by a backslash) or is literally the last occurrence of the substring "index".
2. **String Ops**: This approach uses basic string operations, such as checking if the string ends with "/index" and then slicing it to remove the last 6 characters.

**Pros and Cons**

**RegExp Replace:**

Pros:

* Can handle more complex cases, such as removing parts of a URL or file path.
* Can be more efficient than string ops for large strings.

Cons:

* Requires escaping special characters (e.g., `.`, `?`) to prevent unexpected behavior.
* May have slower performance due to the overhead of regular expressions.

**String Ops:**

Pros:

* Is simpler and easier to understand than RegExp replace.
* Does not require escaping special characters, making it faster for simple cases.

Cons:

* May be less efficient than RegExp replace for complex cases.
* Requires explicit checks for string boundaries (e.g., `.endsWith()`).

**Library used**

In this benchmark, the `replace()` method is used, which is a built-in JavaScript method. No external library is required.

**Special JS feature or syntax**

There are no special JavaScript features or syntaxes used in these benchmarks beyond what is standard for modern JavaScript.

**Other alternatives**

Other approaches to remove the last part of a string might include:

1. **Substrings**: Using the `substring()` method to extract a subset of characters from the original string.
2. **Slicing**: Using the `slice()` method to extract a subset of characters from the original string, similar to `String Ops`.
3. **Regex alternatives**: Using alternative regular expression patterns, such as `\bindex\b` or `[^\w]`, to remove the last part of the string.

These alternatives may have their own pros and cons, which would be worth exploring in a separate benchmarking exercise.

Latest run results:

Run details: (Test run date: 3 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36

Browser/OS: Chrome 127 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
RegExp replace	4351416.0 Ops/sec
String ops	11359012.0 Ops/sec

Related benchmarks:

RegExp replace vs string ops (version: 2)

Comparing performance of: RegExp replace vs String ops

Created: 3 months ago by: Registered User

Jump to the latest result

RegExp replace

String ops

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):