Paper money is just a form of money, while foreign exchange is just foreign currency. All belong to currency, and all four functions are available.

Credit card, to be exact, is the relationship between you and the bank, and the bank lends you money. So in the final analysis, the credit card is not the function, but the credit line given to you by the bank, that is, the money lent to you, which embodies all the functions of money.

Finally, a check is a means of payment.