PHP Generators. e.g.: getSymbol

gistfile1.php

$str = "learning trails provide you with everything you need to..";
foreach(Util::getSymbol($str, 0) as $cur){
    echo Util::charToHex($cur); // 6C6561726E696E672074...
}

...

/**
 * @param string $str
 * @param int $start
 */
public static function getSymbol(&$str, $start = 0)
{
    while(isset($str{$start})){
        yield $str{$start++};
    }
}

public static function charToHex($char)
{
    return sprintf("%02X", ord($char));
}