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

fetch('/connect')

Answer

localStorage.getItem('wallet')

Answer

navigator.connectWallet()

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

It sets the gas limit

Answer

It encrypts the transaction

Answer

It registers the user's email

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

To pay gas fees

Answer

To deploy the contract

Answer

To compile Solidity

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

Increase the gas limit

Answer

Send the transaction twice

Answer

Disable JavaScript

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

Only a JSON-RPC provider

Answer

A private key hardcoded in the frontend

Answer

An Infura API key in the HTML

Question 6

Why is it risky to display 'mint successful' immediately after calling the contract method without awaiting the receipt?

Accepted Answer

The transaction may still revert or be dropped before confirmation

Answer

It uses too much memory

Answer

It violates CORS

Answer

It changes the chainId

Question 7

What does the EIP-1193 'chainChanged' event allow a dApp frontend to do?

Accepted Answer

Detect when the user switches networks and refresh or reload state

Answer

Mint tokens automatically

Answer

Sign the user out of MetaMask

Answer

Lower gas prices