NFT On-Chain Royalties (EIP-2981) 2

Question 1

What does the royaltyInfo function in EIP-2981 return?

Accepted Answer

The receiver address and royalty amount

Answer

royaltyInfo returns a tuple of the receiver address and the royalty amount owed for a given sale price.

Question 2

Which two parameters does royaltyInfo take as inputs?

Accepted Answer

tokenId and salePrice

Answer

royaltyInfo accepts a _tokenId and a _salePrice to compute the royalty owed.

Question 3

EIP-2981 expresses royalties in what unit relative to sale price?

Accepted Answer

An absolute amount derived from the sale price you pass in

Answer

The standard returns an absolute royaltyAmount computed from the salePrice argument, in the same unit of exchange.

Question 4

How is EIP-2981 support advertised to other contracts?

Accepted Answer

Via ERC-165 supportsInterface with the 2981 interface ID

Answer

Contracts signal EIP-2981 compliance through ERC-165's supportsInterface using the standard's interface identifier.

Question 5

What is the ERC-165 interface ID for EIP-2981?

Accepted Answer

0x2a55205a

Answer

0x2a55205a is the interface ID corresponding to the royaltyInfo selector for EIP-2981.

NFT Development Practice Test