FREE Blockchain Developer Token Standards and NFTs Questions and Answers Flashcards
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Read the first 6 FREE Blockchain Developer Token Standards and NFTs Questions and Answers flashcards as text
Which ERC standard introduced the concept of semi-fungible tokens by combining fungible and non-fungible token functionality in a single contract?
Answer: ERC-1155
ERC-1155 is a multi-token standard that supports both fungible and non-fungible tokens within one contract, making them semi-fungible.
What function in the ERC-721 standard is used to safely transfer an NFT while ensuring the recipient contract can handle it?
Answer: safeTransferFrom
safeTransferFrom checks whether the recipient implements the ERC721Receiver interface, preventing tokens from being locked in incompatible contracts.
In ERC-20, what happens if a user calls transfer() with an amount exceeding their balance?
Answer: The transaction reverts
The ERC-20 transfer function will revert the entire transaction if the sender's balance is insufficient.
What is the primary purpose of the tokenURI function in ERC-721?
Answer: To return a URI pointing to the token's metadata
The tokenURI function returns a URI that points to a JSON file containing the NFT's metadata such as name, description, and image.
Which vulnerability can occur when an ERC-20 token's approve function is called to change an existing allowance without first setting it to zero?
Answer: Front-running double-spend attack
A spender can front-run the approve transaction to spend both the old and new allowance, resulting in a double-spend.
What does the ERC-2981 standard define for NFTs?
Answer: A standardized royalty payment interface
ERC-2981 provides a standard way to retrieve royalty payment information for NFTs, enabling marketplaces to honor creator royalties.