Benchmark: regex vs startsWith vs indexOf perf on url

Script Preparation code:

const urls = ['/pl/sdkjfdhsalkjhas', '/go/lasdkfhaskljdhflaksjdhflaksjhdf', '/FI/FI/OFEJ'];
const STARTS_WITH = ['/go/', '/pl'];
const EQUALS = ['/FI/FI/OFEJ', '/fi/fi/ofej'];
const ex = /^\/(go\/|pl\/|FI\/FI\/OFEJ)\W*/;

Tests:

indexOf
const urls = ['/pl/sdkjfdhsalkjhas', '/go/lasdkfhaskljdhflaksjdhflaksjhdf', '/FI/FI/OFEJ']; const STARTS_WITH = ['/go/', '/pl']; const EQUALS = ['/FI/FI/OFEJ', '/fi/fi/ofej']; urls.map(url => STARTS_WITH.filter((starts) => url.indexOf(starts) !== -1)).length > 0;
startsWith
const urls = ['/pl/sdkjfdhsalkjhas', '/go/lasdkfhaskljdhflaksjdhflaksjhdf', '/FI/FI/OFEJ']; const STARTS_WITH = ['/go/', '/pl']; const EQUALS = ['/FI/FI/OFEJ', '/fi/fi/ofej']; urls.map(url => STARTS_WITH.filter((starts) => url.startsWith(starts) !== -1)).length > 0;
regex
const urls = ['/pl/sdkjfdhsalkjhas', '/go/lasdkfhaskljdhflaksjdhflaksjhdf', '/FI/FI/OFEJ']; const STARTS_WITH = ['/go/', '/pl']; const EQUALS = ['/FI/FI/OFEJ', '/fi/fi/ofej']; const ex = /^\/(go\/|pl\/|FI\/FI\/OFEJ)\W*/; urls.map(url => STARTS_WITH.filter((starts) => url.match(ex) !== -1)).length > 0;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
indexOf
startsWith
regex

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 break down the provided benchmark JSON and explain what is being tested, compared, and their pros/cons.

**Benchmark Definition**

The benchmark tests the performance of three different approaches to check if a URL path matches a certain pattern:

1. `startsWith`: Checks if the URL starts with a specific prefix.
2. `indexOf`: Finds the index of the first occurrence of a substring within the URL.
3. `regex`: Uses a regular expression to match the URL against a pattern.

**Comparison**

The benchmark compares the performance of these three approaches on a set of URLs, including:

* `/pl/sdkjfdhsalkjhas`
* `/go/lasdkfhaskljdhflaksjdhflaksjhdf`
* `/FI/FI/OFEJ`

**Options Compared**

1. **startsWith**: Compares the number of executions per second for `startsWith` with each URL.
2. **indexOf**: Compares the number of executions per second for `indexOf` with each URL.
3. **regex**: Compares the number of executions per second for a custom regular expression (`ex`) with each URL.

**Pros and Cons**

1. **startsWith**:
	* Pros: Simple and efficient, as it only checks if the URL starts with a specific prefix.
	* Cons: May not match URLs that have multiple prefixes or a non-alphabetic first character.
2. **indexOf**:
	* Pros: Fast and efficient, as it finds the index of the first occurrence of a substring within the URL.
	* Cons: May return -1 if the substring is not found, which could lead to false positives in some cases.
3. **regex**:
	* Pros: Highly flexible and powerful, allowing for complex patterns and matching.
	* Cons: Can be slower than `startsWith` or `indexOf`, especially for simple patterns.

**Library Used**

None, as this benchmark uses built-in JavaScript functions (`startsWith`, `indexOf`) and a custom regular expression.

**Special JS Feature/Syntax**

No special JavaScript features or syntax are used in this benchmark.

**Other Alternatives**

Other approaches to check URL path matching could include:

1. **Substrings**: Similar to `startsWith` but allows for multiple prefixes.
2. **Regex alternatives**: Other regex engines like PCRE (Perl-Compatible Regular Expressions) might be faster or more efficient than the custom regex used here.
3. **URL parsing libraries**: Libraries like URL-Parser or url-parse can parse URLs and extract path information, potentially reducing the complexity of the benchmark.

Keep in mind that this is a simplified explanation, and there are many nuances to consider when optimizing JavaScript performance.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36

Browser/OS: Chrome 111 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
indexOf	6536526.5 Ops/sec
startsWith	9959996.0 Ops/sec
regex	2906134.0 Ops/sec

Related benchmarks:

regex vs startsWith vs indexOf perf on url (version: 0)

compare url path matching perf

Comparing performance of: indexOf vs startsWith vs regex

Created: 2 years ago by: Guest

Jump to the latest result

indexOf

startsWith

regex

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):