How we can get the user id by its display_name

Question

I have user display_name and with this I want to get the id of that user.

So, how can I get the user id?

Answer 1

Use WP_User_Query.

$args= array(
  'search' => 'Display Name', // or login or nicename in this example
  'search_fields' => array('user_login','user_nicename','display_name')
);
$user = new WP_User_Query($args);

Just answered one very similar to this: How we can get the author ID by its Name

Answer 2

You can use the following function:

function get_user_id_by_display_name( $display_name ) {
    global $wpdb;

    if ( ! $user = $wpdb->get_row( $wpdb->prepare(
        "SELECT `ID` FROM $wpdb->users WHERE `display_name` = %s", $display_name
    ) ) )
        return false;

    return $user->ID;
}

This is the same code get_user_by() uses, but since that function only allows ID, slug, email or login we have to create a new function.

Answer 3

Completely untested, but I can't see anything in the code why it wouldn't work to use get_users() with a meta query:

$users = get_users( array(
    'meta_key' => 'display_name',
    'meta_value' => 'John Doe'
) );

$user = ( ( isset( $users[0] ) ? $users[0] : false );

$user_id = ( $user ? $user->ID : false );