Converting Arabic to Roman Numerals

Both class methods are static; you do not need to instantiate an object.

The static method toNumeral does exactly this. It can be used for numbers from 1 to 5 999 999. Using it to convert higher numbers works, but does not produce historically correct results.

The second parameter $uppercase determines if the letters should be UPPERCASE (default) or not. Parameter number 3 sets if HTML code for overscores shall be generated; this is necessary for numbers greater than 3999. If the parameter is set to false, letters will be prefixed with an underscore _.

Converting Arabic numbers to Roman numerals

require_once 'Numbers/Roman.php';

//returns: XXIII

echo Numbers_Roman::toNumeral(23false);
//returns: xxiii