I am a swede, so I don't really know how tourist do it. But I just use my debit card for almost everything. For buses/trains/taxis I use cards/or the their app

I am a swede, so I don't really know how tourist do it. But I just use my debit card for almost everything. For buses/trains/taxis I use cards/or the their app which will take cards. For the random $4 street vendor hotdog we use swish (https://www.getswish.se/ https://www.getswish.se/).