How to Hide WordPress Login Errors

When someone failed to login into your WordPress admin area (dashboard), WordPress displays an error message describing the reason for that. Some way these information may be helpful to a hacker to find correct username and password for your WordPress admin area. Look at this example error message:

So if you don’t want to reveal to users that they are using the wrong username or the wrong password, here is a quick tip to hide WordPress login errors.
Paste the following line of code into your theme's functions.php file:

add_filter('login_errors', create_function('$a', "return null;"));

Now WordPress login errors will not be displayed when someone enter wrong login details.