Pretty print fractions as HTML characters using PHP

index.php

//from post at http://davidnash.com.au/pretty-print-fractions-html-characters-using-php/

//supply a string, eg 1/2, return eg ½
function str_to_fraction( $str ) {
	$f = explode('/', $str);

	if( count($f) != 2 ) {
		return $str; //if there's multiply / chars, this isn't a fraction
	}
	else {

		//return single html entities where they exist
		if( $f[0] == 1 && ( $f[1] == 2 || $f[1] == 4 ) ) {
			// 1/2, 1/4
			return '&frac1'.$f[1].';';
		}
		else if( $f[0] == 3 && $f[1] == 4 ) {
			// 3/4
			return '¾';
		}
		else {
		
			if( $f[1] == 8 ) {
				if( $f[0] == 1 )
					return '⅛'; // 1/8
				else if( $f[0] == 3 )
					return '⅜'; // 3/8
				else if( $f[0] == 5 )
					return '⅝'; // 5/8
				else if( $f[0] == 7 )
					return '⅞'; // 7/8
			}

			//else it's a crazy fraction, but we can handle that:
			return "<sup>$f[0]</sup>&frasl;<sub>$f[1]</sub>";
		}

	} //end if a string of form X/Y

} //str_to_fraction()