Token Standards and NFTs Flashcards
7 cards from real Blockchain Technology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Token Standards and NFTs flashcards as text
Which ERC standard introduced a single contract capable of managing multiple token types, both fungible and non-fungible?
Answer: ERC-1155
ERC-1155 is the multi-token standard allowing one contract to handle fungible, non-fungible, and semi-fungible tokens.
In ERC-721, what function returns the owner of a specific token ID?
Answer: ownerOf
ownerOf(tokenId) returns the address that owns the given NFT.
What does the ERC-721 metadata function tokenURI typically return?
Answer: A URI pointing to a JSON metadata file
tokenURI returns a URI that resolves to JSON metadata describing the asset (name, image, attributes).
Why is ERC-1155 considered more gas-efficient than deploying many ERC-721 contracts?
Answer: It supports batch transfers of multiple token types in one call
ERC-1155's safeBatchTransferFrom moves multiple token IDs and amounts in a single transaction, reducing gas.
Which interface detection standard do ERC-721 contracts implement so others can query supported interfaces?
Answer: ERC-165
ERC-165 defines supportsInterface, used to advertise which interfaces (like ERC-721) a contract implements.
In ERC-1155, what does the balanceOf function require as arguments?
Answer: An address and a token ID
Because one contract holds many token types, balanceOf(account, id) needs both the holder and the specific id.
What is a key risk of storing NFT metadata at a centralized HTTP URL rather than on IPFS?
Answer: The metadata/image can change or disappear, breaking the NFT
Centralized URLs are mutable and can go offline, so the referenced image or data may change or vanish.