NFT Frontend Minting and Integration 2

Question 1

In a React dApp, which library function is most commonly used to connect a browser wallet via injected providers like MetaMask?

Accepted Answer

window.ethereum.request({ method: 'eth_requestAccounts' })

Answer

EIP-1193 providers expose window.ethereum, and eth_requestAccounts prompts the user to connect their accounts.

Question 2

When minting an NFT from the frontend, why should the total mint cost (price × quantity) be sent in the transaction's 'value' field?

Accepted Answer

The contract's payable mint function requires ETH to cover the price

Answer

A payable mint function expects msg.value to equal the required payment, so the value field must carry the ETH.

Question 3

What is the purpose of listening to a contract's 'Transfer' event after a mint transaction confirms on the frontend?

Accepted Answer

To detect the newly minted tokenId and update the UI

Answer

The Transfer event from the zero address signals a mint and exposes the new tokenId for UI updates.

Question 4

Which approach prevents a user from being charged for a failed mint when the sale is paused on-chain?

Accepted Answer

Call a read-only view (e.g., saleActive) before sending the transaction

Answer

Reading the sale state first lets the UI block transactions that would revert, saving the user gas.

Question 5

In ethers.js v6, what does a 'Contract' instance need to send a state-changing mint transaction rather than just read data?

Accepted Answer

A signer connected to the contract

Answer

Read calls work with a provider, but write transactions require a signer that can authorize and submit them.

NFT Development Practice Test