app/Filters/Book/DifficultyFilter.php
/**
     * Mappings for database values.
     *
     * @return array
     */
Mappings for database values.
@return array
Mappings for database values . @return array
public function mappings()
    {
        return [
            'beginner' => 'beginner',
            'intermediate' => 'intermediate',
            'advanced' => 'advanced',
        ];
    }
public function mappings ( ) { return [ 'beginner' => 'beginner' , 'intermediate' => 'intermediate' , 'advanced' => 'advanced' , ] ; }
Mappings for database values.
Mappings for database values .