They only accept Saudi currency at the airport. You can pay by CC at the duty free shops but not the restaurant and the coffee shop. They accept foreign currency but FX rate is horrible!
Rich country with very bad airport systems, facilities and staffs. Beware of trolley workers who will 'lend' their hand and will ask for money after 'helping' you.
لا زال المطار سيئ، رحلات متاخره، رحت للبوابه لانهم اعلنوا على رحلتي ومكتوب بالشاشة boarding, ومكتوب على البوابه رقم الرحلة والناس صافه سرا، وبالاخير الرحلة متاخره وقاعدين يدخلون رحلة ثانية!!.