Regular expression in php to find roman numerals

Hey folks,

I stumbled upon this thread and thought I'd share a different approach I used to identify Roman numerals in PHP. Instead of relying on regular expressions, I found it more effective to utilize the `IntlChar` class introduced in PHP 7.

Here's a code snippet to demonstrate how you can leverage the `IntlChar` class to find Roman numerals:

php
function findRomanNumerals($text) {

    $result = [];

    $textLength = mb_strlen($text, 'UTF-8');

  

    for ($i = 0; $i < $textLength; $i++) {

        $currentChar = mb_substr($text, $i, 1, 'UTF-8');

        $charCode = IntlChar::ord($currentChar);

        

        if (IntlChar::hasBinaryProperty($charCode, IntlChar::PROPERTY_NUMERIC_TYPE)

            && IntlChar::getIntPropertyValue($charCode, IntlChar::PROPERTY_NUMERIC_TYPE) === IntlChar::DOUBLE_WIDTH)

        {

            $result[] = $currentChar;

        }

    }

    

    return $result;

}



$romanNumerals = findRomanNumerals($text);



if (!empty($romanNumerals)) {

    // Roman numerals found!

    // Process the numerals accordingly

} else {

    // No Roman numerals found

}

Hey there!

I've had a similar need in one of my previous projects, and I managed to come up with a regular expression that worked well for me. Here's what I used:

php
$pattern = '/^(M{0,3})(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})$/';



if (preg_match($pattern, $text)) {

    // Roman numeral found!

    // Do something with it

} else {

    // No Roman numerals found

}

More Topics Related to PHP

• What are the recommended PHP versions for different operating systems?
• Can I install PHP without root/administrator access?
• How can I verify the integrity of the PHP installation files?
• Are there any specific considerations when installing PHP on a shared hosting environment?
• Is it possible to install PHP alongside other programming languages like Python or Ruby?

More Topics Related to Regular Expression

• regular expression in php: take the shortest match
• PHP regular expression to extract TwitPic link/code if present
• Correct way to add comments to a Regular Expression in PHP
• PHP Regular expression for North/South/East/West
• explode - PHP Regular expression for star '*'