How getApproved return correct address to correct marketplace??

[Muhammad-Abdullah012]

I've a question regarding this code.

 IERC721 nft = IERC721(nftAddress);
 if (nft.getApproved(tokenId) != address(this)) {
    revert NftMarketplace__NotApprovedForMarketplace();
 }

nft.getApproved(tokenId) returns approved address for an NFT.

Now if a user approve it's NFT for multiple marketplaces and put for sale on all of them,...
Then there will be more than one approved addresses for one NFT.
For example:
A person approves two marketplaces A and B and put NFT for sale on both. Now if marketplace A call nft.getApproved(tokenId) to check if it is approved. Then how will NFT return address of marketplace A, to it??

How will NFT return approved address to correct marketplace???

Will it check to see if caller contract is in a map (or some other data structure), if it's there, it return caller's address, otherwise return address(0)??

[technophile-04]

Hii, _tokenApprovals is mapping used to track approvals for a particular token ID and its 1-1 it means that at particular instance of time there can be only one approved address(Marketplace)....So if you first approve A and then approve B the address of marketplcae B will override the _tokenApprovals mapping for that tokenId...And when you call getApproved(tokenId) function it returns this _tokenApprovals[tokenId] in our case it will return address of B
You can take a look at this function implementd here : https://github.com/OpenZeppelin/openzeppelin-contracts/blob/ec825d8999538f110e572605dc56ef7bf44cc574/contracts/token/ERC721/ERC721.sol#L127