get id from username wp getuserby

To get the user ID from a username in WordPress, you can use the get_user_by() function. Here's an example:

$username = 'john.doe';
$user = get_user_by( 'login', $username );
if ( $user ) {
    $user_id = $user->ID;
    echo "The user ID for $username is $user_id.";
} else {
    echo "User $username not found.";
}

In this example, we're looking up the user with the username 'john.doe' using the 'login' parameter of get_user_by(). If the user is found, we retrieve their ID from the $user object and print it out. If the user is not found, we print a message saying so