Benchmark: OnlyLetterAndNumbers c# regex vs loop

HTML Preparation code:

var string = "ThisIsStringWithOnlyLettersAndNumbers_АТакЖе-И_БезПробеловИТочек";

Script Preparation code:

var string = "ThisIsStringWithOnlyLettersAndNumbers_АТакЖе-И_БезПробеловИТочек";

Tests:

RegEx
let isValidTag = false; const number = new RegExp("^[A-Za-zА-Яа-яЁё0-9_\-]+$"); isValidTag = number.test(string);
Loop
let isValidTag = true; let alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzАБВГДЕЁЖЗИЙКЛМНОПРСТУФХЦШЩЪЫЬЭЮЯабвгдеёжзийклмнопрстуфхцшщъыьэюя0123456789-_"; for (let i = 0; i < string.length; i++) { let chr = string.charAt(i); if (alphabet.indexOf(chr) == -1) { isPasswordValid = false; break; } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
RegEx
Loop

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 27 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0

Browser/OS: Firefox 128 on Windows

View result in a separate tab

Test name	Executions per second
RegEx	3805696.5 Ops/sec
Loop	589176.4 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and considered.

**Benchmark Overview**

The benchmark compares two approaches to validate a string that only contains letters and numbers:

1. **Regex (Regular Expression)**
2. **Looping through characters**

**Options Compared**

* **Regex**: Uses a regular expression pattern to match the entire string against a set of allowed characters.
* **Looping through characters**: Iterates over each character in the string and checks if it's within a predefined alphabet of allowed characters.

**Pros and Cons of Each Approach**

**Regex:**

Pros:

* Typically faster than looping through characters, as it can use optimized matching algorithms.
* Can be more concise and expressive for complex patterns.

Cons:

* May be slower for very short strings or simple patterns due to the overhead of creating a regular expression object.
* Can be less intuitive for beginners without experience with regular expressions.

**Looping through Characters:**

Pros:

* Guaranteed to work correctly for any string, regardless of length or complexity.
* Easy to understand and implement for those familiar with basic looping constructs.

Cons:

* Typically slower than using a regex due to the overhead of checking each character individually.
* Can be less concise and more verbose for complex patterns.

**Other Considerations**

* **Performance**: The benchmark provides execution counts per second, which indicates performance differences between the two approaches. In this case, the regex approach is significantly faster (207,721,414 executions/second vs 97,760 executions/second).
* **Readability and Maintainability**: The looping through characters approach might be more readable for those unfamiliar with regular expressions or complex patterns.

**Library Used**

The benchmark uses JavaScript's built-in `RegExp` object to create a regular expression pattern. The purpose of this library is to provide a concise way to define patterns and perform matching operations on strings.

**Special JS Feature/Syntax**

None mentioned in the provided benchmark code, but it's worth noting that some modern browsers have introduced features like `String.prototype.match()` or `Array.prototype.find()`, which could potentially be used for string validation. However, their performance characteristics might vary depending on the specific use case and implementation.

**Alternatives**

Other alternatives for validating strings based on a set of allowed characters include:

* **Using a custom string validation function**: Creating a dedicated function to check if each character is within the allowed alphabet.
* **Utilizing a library like `lodash` or ` moment`**: These libraries provide utility functions, including string validation methods.
* **Regular expression alternatives**: Depending on the specific use case and performance requirements, alternative regex patterns might be more suitable (e.g., using `\w` instead of `^[A-Za-zА-Яа-яЁё0-9_\-]+$`).

In conclusion, this benchmark highlights the trade-offs between using regular expressions for string validation versus looping through characters. While regex can provide a concise and expressive way to define patterns, it may not always be the fastest approach. The choice ultimately depends on performance requirements, readability concerns, and personal familiarity with each method.

Related benchmarks:

OnlyLetterAndNumbers c# regex vs loop (version: 0)

Comparing performance of: RegEx vs Loop

Created: one year ago by: Guest

Jump to the latest result

RegEx

Loop

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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