Question

Using PHP, I have to detect ‘” (single quotation mark followed by double quotation mark) to prevent XSS.
thus, I implemented below function.

function xss_cleaner_new($input_str){
    $return_str = preg_replace('/"\'/','&l', &input_str);
    return $return_str;
}

However, it seems to detect only (first single quotation mark) rather than (single quotation mark followed by double quotation mark)

How can I detect ‘”(single quotation mark followed by double quotation mark) sucessfully?

Answer 1

Try this:

preg_replace("/'\"/","&l",$input_str);