NFT Guide 2

Question 1

Which Ethereum standard is the foundation for non-fungible tokens?

Accepted Answer

ERC-721

Answer

ERC-721 defines the standard interface for unique, non-fungible tokens.

Question 2

What does the tokenURI function in an ERC-721 contract typically return?

Accepted Answer

A pointer to the token's metadata

Answer

tokenURI returns a URI pointing to a JSON file describing the token's metadata.

Question 3

Why do many NFT projects store metadata and images on IPFS instead of a centralized server?

Accepted Answer

It provides content-addressed, tamper-resistant storage

Answer

IPFS uses content hashes so data cannot be silently changed, improving permanence and trust.

Question 4

In a typical NFT mint function, what is commonly enforced to prevent abuse?

Accepted Answer

A maximum supply and per-wallet limit

Answer

Mint functions usually cap total supply and limit how many tokens one wallet can mint.

Question 5

What is the purpose of the _safeMint function in OpenZeppelin's ERC-721 implementation?

Accepted Answer

It checks the recipient can receive ERC-721 tokens

Answer

_safeMint verifies that contract recipients implement onERC721Received to avoid locked tokens.

NFT Development Practice Test