WP_User::__isset() │ public │ WP 3.3.0

Magic method for checking the existence of a certain custom field.

Method of the class: WP_User{}

No Hooks.

Return

true|false. Whether the given user meta key is set.

Usage

$WP_User = new WP_User();
$WP_User->__isset( $key );
$key(string) (required)
User meta key to check if set.

Changelog

Since 3.3.0 Introduced.

WP_User::__isset() code WP 6.6.2

wp-includes/class-wp-user.php 
public function __isset( $key ) {
	if ( 'id' === $key ) {
		_deprecated_argument(
			'WP_User->id',
			'2.1.0',
			sprintf(
				/* translators: %s: WP_User->ID */
				__( 'Use %s instead.' ),
				'<code>WP_User->ID</code>'
			)
		);
		$key = 'ID';
	}

	if ( isset( $this->data->$key ) ) {
		return true;
	}

	if ( isset( self::$back_compat_keys[ $key ] ) ) {
		$key = self::$back_compat_keys[ $key ];
	}

	return metadata_exists( 'user', $this->ID, $key );
}