Is an NFT’s position in the list its number?
After selecting an item from an NFT list, don’t assume its position is the number of that NFT.
The ERC-721 standard in the $ETH ecosystem provides an optional enumeration feature: when you enter a position in the list, the interface returns the NFT number corresponding to that position. The input is a position; the number is what gets returned. The two are not interchangeable.
The standard also does not specify how the list is sorted. The same applies to interfaces that enumerate the NFTs owned by a particular holder. Just because an NFT appears near the top doesn’t mean you can assign it a smaller number.
If you use a query tool to organize a collection, first retrieve the actual number returned by the interface, then use it to query or verify subsequent actions. When developing a page, keep list positions and asset numbers in separate fields too, so you don’t select one image and then look up a different number.
This explains the standard’s enumeration interfaces; it does not inspect specific marketplace pages or the value of any collection.
Source: https://eips.ethereum.org/EIPS/eip-721
After selecting an item from an NFT list, don’t assume its position is the number of that NFT.
The ERC-721 standard in the $ETH ecosystem provides an optional enumeration feature: when you enter a position in the list, the interface returns the NFT number corresponding to that position. The input is a position; the number is what gets returned. The two are not interchangeable.
The standard also does not specify how the list is sorted. The same applies to interfaces that enumerate the NFTs owned by a particular holder. Just because an NFT appears near the top doesn’t mean you can assign it a smaller number.
If you use a query tool to organize a collection, first retrieve the actual number returned by the interface, then use it to query or verify subsequent actions. When developing a page, keep list positions and asset numbers in separate fields too, so you don’t select one image and then look up a different number.
This explains the standard’s enumeration interfaces; it does not inspect specific marketplace pages or the value of any collection.
Source: https://eips.ethereum.org/EIPS/eip-721