dnb-prospectus/src/Questionaire.php

<?php

namespace DNB;

class Questionaire extends AbstractPostSerializable implements PostSerializableInterface {
    public function __construct(
        private ?bool $keepMeInformedOnBids = null,
        private ?bool $contactForPropertyValuation = null,
        private ?bool $contactForEconomicalAdvice = null,
    ){}

    public function toPostParams(): array {
        $arr = [];

        foreach (static::getClassVars() as $key)
            $arr[$key] = !is_null($this->{$key}) ? $this->{$key} : false;

        return $arr;
    }

    protected static function getClassVars(): array {
        return array_keys(get_class_vars(__CLASS__));
    }
}