NFT Skills 3

Question 1

What distinguishes the ERC-1155 standard from ERC-721?

Accepted Answer

ERC-1155 supports both fungible and non-fungible tokens in a single contract

Answer

ERC-1155 is a multi-token standard allowing fungible, semi-fungible, and non-fungible tokens within one contract.

Question 2

Which tool would a developer use to connect a web front-end to the Ethereum blockchain and a user's wallet?

Accepted Answer

ethers.js or web3.js

Answer

Libraries like ethers.js and web3.js let dApps interact with smart contracts and wallets in the browser.

Question 3

What is a 'reentrancy' vulnerability in smart contract development?

Accepted Answer

An attack where an external call re-enters the contract before state updates complete

Answer

Reentrancy occurs when a malicious contract calls back into the original function before its state changes finalize, draining funds.

Question 4

Which pattern helps prevent reentrancy attacks in Solidity?

Accepted Answer

Checks-Effects-Interactions

Answer

The checks-effects-interactions pattern updates state before making external calls, mitigating reentrancy.

Question 5

What does 'gas' represent when deploying or interacting with an NFT contract?

Accepted Answer

The unit measuring computational work and its fee on Ethereum

Answer

Gas measures computational effort, and users pay a gas fee to execute transactions on Ethereum.

NFT Development Practice Test