Question

At the moment I have:

//replace common characters
$search = array('&', '£', '$'); 
$replace = array('&', '£', '$'); 
$html= str_replace($search, $replace, $html);

The problem with this code is that if the & has been already converted it will try to convert it again. How would I make sure this doesn’t happen?

Answer 1

i give an example but it will work if you have the latter like ' & ' then hope this will work for you:

$str = 'India & Aust & New ';
$regex = '/(\s\&\s)/i';
$replace = ' & ';

if(preg_match($regex, $str)){
    $new_str = preg_replace($regex, $replace, $str );

    echo '<pre>';
    echo htmlspecialchars($new_str, ENT_QUOTES);
    echo '</pre>';
}
else{
    echo 'Not matched!';
}

but remember this will work if you have space on both sides of an ampersand or whatever you want. Otherwise follow the @Treffynnon Answer..