Question

I have a string and the validity of the string is defined as:

1. The string can have alphanumeric characters or (_) or (.) or (-).
2. No other special characters are allowed.

Is there a way to allow only certain special characters in php??

Answer 1

You can use code like this to only allow a text with your allowed character set:

if (preg_match('/^[\w.-]+$/', $str))
    echo "valid $str\n";
else
    echo "invalid $str\n";