Mastering Blockchain Programming with Solidity

The ERC721 NFT standard API interface

The specification of the ERC721 standard interface that we are discussing in this section is taken from the EIP standard document at https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md.

The ERC721 NFT standard interface is defined as follows:

interface ERC721 is ERC165 {    event Transfer(address indexed _from, address indexed _to,                    uint256 indexed _tokenId);    event Approval(address indexed _owner, address indexed _approved,                    uint256 indexed _tokenId);    event ApprovalForAll(address indexed _owner, address indexed _operator,                          bool _approved);    function balanceOf(address _owner) external view returns (uint256);    function ownerOf(uint256 _tokenId) external view returns (address);    function safeTransferFrom ...