Minting and Burning Mechanics Flashcards

In ERC-721, which internal function is typically called to create a new token and assign it to an address?

Answer: _mint(to, tokenId)

_mint(to, tokenId) creates a new token and assigns ownership to the given address.

What event must be emitted when a token is minted in a compliant ERC-721 contract?

Answer: Transfer event with from set to the zero address

Minting emits a Transfer event where the 'from' address is the zero address.

When a token is burned in ERC-721, what is the 'to' address in the emitted Transfer event?

Answer: The zero address (0x0)

Burning emits a Transfer event to the zero address, removing the token from circulation.

Why does OpenZeppelin's _mint revert if the destination is the zero address?

Answer: Minting to address(0) would be indistinguishable from a burn

Allowing a mint to the zero address would collide with the convention that burns target address(0).

What happens to the totalSupply tracking when a token is burned in an enumerable ERC-721?

Answer: It decreases by one

Burning reduces the total supply count in enumerable implementations.

Which access control pattern best restricts who can call a mint function?

Answer: A modifier like onlyOwner or onlyRole(MINTER_ROLE)

Role or ownership modifiers restrict minting to authorized addresses.

In a burn function, what check should occur before destroying a token?

Answer: That the caller is the owner or approved for the token

Only the owner or an approved operator should be permitted to burn a token.