get_user_by

The get_user_by function is a WordPress function that is used to retrieve a user object by searching for a specific value in a specified field. This function is commonly used in WordPress development when working with user authentication or when retrieving user information.

The function requires two parameters: $field and $value. The $field parameter specifies which field to search for the value in, and the $value parameter is the value being searched for. The function returns a WP_User object if a user is found, or null if no user is found.

Here is an example usage code:

$user = get_user_by( 'email', 'user@example.com' );
if ( $user ) {
    echo 'User ID is: ' . $user->ID;
}

In this example, we are searching for a user by their email address. If a user with the email address user@example.com is found, their user ID will be echoed to the page.

Another possible usage of the function could be to search for a user by their username, like this:

$user = get_user_by( 'login', 'john_doe' );
if ( $user ) {
    echo 'User email is: ' . $user->user_email;
}

In this case, we are searching for a user with the username john_doe. If a user is found, their email address will be echoed to the page.

Learn More on WordPress.org