NFT Advanced NFT Mechanics 2

Question 1

In ERC-721, which function is used to safely transfer a token while checking that the recipient contract can handle ERC-721 tokens?

Accepted Answer

safeTransferFrom

Answer

transferFrom

Answer

approve

Answer

setApprovalForAll

Question 2

What does the ERC-2981 standard add to NFT contracts?

Accepted Answer

Royalty payment information

Answer

On-chain metadata storage

Answer

Batch minting support

Answer

Soulbound enforcement

Question 3

Which interface must a contract implement to be recognized for capability detection like ERC-721 support?

Accepted Answer

ERC-165

Answer

ERC-20

Answer

ERC-777

Answer

ERC-1167

Question 4

In ERC-1155, why is balanceOfBatch more gas-efficient than multiple balanceOf calls?

Accepted Answer

It queries multiple token IDs in one call

Answer

It caches results off-chain

Answer

It skips storage reads

Answer

It uses a different opcode

Question 5

What is a common purpose of a tokenURI returning an IPFS hash rather than an HTTP URL?

Accepted Answer

Content-addressed immutability

Answer

Faster minting

Answer

Lower gas fees

Answer

Built-in royalties

Question 6

Which event must ERC-721 emit when ownership of a token changes?

Accepted Answer

Transfer

Answer

Approval

Answer

Mint

Answer

OwnershipChanged

Question 7

What is the main advantage of lazy minting?

Accepted Answer

Minting gas is deferred until first purchase

Answer

Tokens mint automatically each block

Answer

It prevents all royalties

Answer

It removes the need for metadata