function to_ascii($string)
{
	$ascii_string = '';
	foreach (str_split($string) as $char) 
	{ 
		$ascii_string .= '&#' . ord($char) . ';'; 
	}
	return $ascii_string;
}

function to_ascii($string)
{ 
    foreach (str_split($string) as $char) 
    { 
        $ascii_string .= '&#' . ord($char) . ';'; 
    }
    return $ascii_string;
}

Convert string to ASCII

php

PHP