Element implicitly has an 'any' type because expression of type 'string' can't be used to index type '{ "31337": string[]; }'

[PatrickAlphaC]

I'm working on the LotteryEntrance.tsx in the nextjs-smartcontract-lottery-fcc and I'm running into this error getting the chainId in my json object:

const { chainId: chainIdHex, isWeb3Enabled } = useMoralis()
const chainId = parseInt(chainIdHex!).toString()
const raffleAddress = chainId in contractAddresses ? contractAddresses[chainId] : null

My VSCode is telling me:

Element implicitly has an 'any' type because expression of type 'string' can't be used to index type '{ "31337": string[]; }'.
  No index signature with a parameter of type 'string' was found on type '{ "31337": string[]; }'.ts(7053)

How do I fix this?

[PatrickAlphaC]

You need to create an interface for the code! Typescript will be confused by the typings otherwise:

interface contractAddressesInterface {
    [key: string]: string[]
}
// some code here
    const addresses: contractAddressesInterface = contractAddresses
    const { chainId: chainIdHex, isWeb3Enabled } = useMoralis()
    const chainId: string = parseInt(chainIdHex!).toString()
    const raffleAddress = chainId in addresses ? addresses[chainId][0] : null