How can I change the tooltip in the_category?

I used this solution instead, within my single.php file:

<?php
//categories loop

$categories = get_the_category();
$separator=", ";
$output="";
if($categories){
    foreach($categories as $category) {
        $output .= '<a href="'.get_category_link( $category->term_id ).'" title="' .     esc_attr( sprintf( __( "%s" ), $category->name ) ) . '">'.$category-    >cat_name.'</a>'.$separator;
    }
echo trim($output, $separator);
}
?>