NFT Art NFT Minting and Smart Contracts 3

Question 1

What is 'gas' in the context of minting an NFT on Ethereum?

Accepted Answer

A fee paid to miners/validators to process and confirm transactions

Answer

Gas is the unit measuring computational work on Ethereum, and users pay gas fees in ETH to compensate validators for processing transactions.

Question 2

An artist discovers their NFT collection smart contract has a reentrancy vulnerability. What does this mean?

Accepted Answer

An attacker can repeatedly call a function before the first execution completes, draining funds

Answer

Reentrancy attacks exploit contracts that send ETH before updating state, allowing attackers to recursively call back into the function.

Question 3

What is the difference between a 'mint' function and a 'safeMint' function in ERC-721?

Accepted Answer

safeMint checks that the recipient can handle ERC-721 tokens if it's a contract address

Answer

safeMint calls onERC721Received on contract recipients to verify they can handle NFTs, preventing tokens from being locked in incompatible contracts.

Question 4

Which of the following best describes a 'smart contract ABI' when interacting with an NFT contract?

Accepted Answer

An interface definition describing the contract's functions and data structures

Answer

The ABI (Application Binary Interface) defines how to encode and decode calls to a contract's functions, acting as the interface between applications and the contract.

Question 5

A generative art NFT project uses a random number to assign traits at mint time. Why is using block.timestamp as randomness dangerous?

Accepted Answer

Miners can manipulate block timestamps to influence trait outcomes

Answer

Block timestamps can be slightly manipulated by miners, allowing them to choose favorable timestamps that produce rare traits for themselves.

NFT - Art Practice Test

NFT - Art Practice Test

NFT Art NFT Minting and Smart Contracts 3