August 2019
Intermediate to advanced
486 pages
13h 52m
English
Content preview from Mastering Blockchain Programming with Solidity
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Understanding ERC721 state variables
The ERC721 contract definition of OpenZeppelin uses some state variables to keep track of the NFTs and their ownership and approvals. It also has some constants defined that are used for the ERC165 standard, so that the client can detect the functions supported by the contract.
Let's look at each of the state variables defined in the contract.