_Follow along with this video:_ --- ### Zero Address Check We're flying through these! Next note that comes up when we search our `@Audit` tag is ... ```js constructor(uint256 _entranceFee, address _feeAddress, uint256 _raffleDuration) ERC721 ("Puppy Raffle, "PR""){ // @Audit: check for zero address! ... } ``` This is another finding `Aderyn` caught for us, we can just copy and paste this write up into our report like so: ````md ### [I-3] Missing checks for `address(0)` when assigning values to address state variables Assigning values to address state variables without checking for `address(0)`. - Found in src/PuppyRaffle.sol [Line: 69](src/PuppyRaffle.sol#L69) ```solidity feeAddress = _feeAddress; ``` - Found in src/PuppyRaffle.sol [Line: 159](src/PuppyRaffle.sol#L159) ```solidity previousWinner = winner; ``` - Found in src/PuppyRaffle.sol [Line: 182](src/PuppyRaffle.sol#L182) ```solidity feeAddress = newFeeAddress; ``` ```` Leveraging our tools is a great way to speed up the write up process. Thanks, `Aderyn`! Mark the note as complete and we'll move on to the next finding! ```js constructor(uint256 _entranceFee, address _feeAddress, uint256 _raffleDuration) ERC721 ("Puppy Raffle, "PR""){ // @Written: check for zero address! ... } ```