_Follow along with this video:_ --- ### Storage Variables in a Loop Should be Cached Searching again for our `@Audit` tag, we should next come across ```js // @Audit-Gas: uint256 playerLength = players.length ``` This finding is pointing to a waste of gas incurred by having to always read from storage. In the `enterRaffle` function, Puppy Raffle is checking for duplicates in an inefficient way. We were going to recommend removing this check entirely elsewhere, but we should still report this gas issue. ````md ### [G-2] Storage Variables in a Loop Should be Cached Everytime you call `players.length` you read from storage, as opposed to memory which is more gas efficient. ```diff + uint256 playersLength = players.length; - for (uint256 i = 0; i < players.length - 1; i++) { + for (uint256 i = 0; i < playersLength - 1; i++) { - for (uint256 j = i + 1; j < players.length; j++) { + for (uint256 j = i + 1; j < playersLength; j++) { require(players[i] != players[j], "PuppyRaffle: Duplicate player"); } } ``` ```` Using a diff shows clearly what adjustments should be made to optimized for gas. Next finding!