Mastering Blockchain Programming with Solidity

The _mint internal function

The _mint() internal function is used to mint a new NFT at the given address. As the function is internal, it can only be used from inherited contracts to mint new tokens.

This function takes the following arguments:

• to: The address of the owner for whom the new NFT is minted
• tokenId: The new tokenId for the token that will be minted

Let's look at the _mint() function code:

function _mint(address to, uint256 tokenId) internal {    require(to != address(0));    require(!_exists(tokenId));    _tokenOwner[tokenId] = to;    _ownedTokensCount[to] = _ownedTokensCount[to].add(1);    emit Transfer(address(0), to, tokenId);}

As you can see in the preceding code, the new tokenId is checked using the _exists() function, which ensures ...