How can I avoid when printing on screen [duplicated]

The problem when they appear that type of strange characters, are always the character sets. I recommend that you continue in link that you put in the comments.

I think that in your specific case what happens is that you enter data directly in phpMyAdmin and when you generate the HTML from those data the characters you mention appear. You can try other tools to manage your DB and the same thing would happen to you (do a search for: "alternatives to phpMyAdmin"), surely the most used is adminer .

The usual solution is to select the appropriate character set at the database level and at the table level, although I think this does not solve the problem by directly entering the data in phpmyadmin, which will not be the usual option in an application real.

A usual configuration when creating a new database would be to select the "Collation": utf8_general_ci

and at the table level, when they are created, I'll give you an example:

CREATE TABLE IF NOT EXISTS 'ciudades' (
    id          int(9)          NOT NULL AUTO_INCREMENT,
    nombre      varchar(255)    NOT NULL,

        PRIMARY KEY (id)) 
        DEFAULT CHARSET=utf8 COLLATE utf8_general_ci;