Allow only [a-z][A-Z][0-9] and some symbols in a string

Question

How can I get a string that only contains a to z, A to Z, 0 to 9 and some symbols?

My string is: ��S�o�n�u� �N�i�g�a�m�,� �S�a�i�n�d�h�a�v�i

I would like to eliminate the symbols.

Answer 1

You can test your string (let $str) using preg_match:

if(preg_match("/^[a-zA-Z0-9]+$/", $str) == 1) {
    // string only contain the a to z , A to Z, 0 to 9
}

If you need more symbols you can add them before ]