How can I know if a account exists or not on solana blockchain in frontend?

Question

I am creating PDA accounts which have seeds consisting of user-wallet-publicKey and a static-text

In frontend I want to show either user-data if user already created his account or a button to deploy new user-related-pda-account, for that I want to know if user already created / deployed account related to him or not

I am generating PDA-address in frontend like this:

const timerProgram = getTimerProgram(provider)
const [timerStatsPDA, _] = await PublicKey.findProgramAddress(
  [
    utils.bytes.utf8.encode('timer_map'),
    provider.wallet.publicKey.toBuffer(),
  ],
  timerProgram.programId
)

I am searching for function similar like this

const isExist = await isAccountExist(timerStatsPDA)

Answer 1

We can use connection.getAccountInfo() as follows to determine if any given account-address exist on blockchain or not

import { useConnection } from '@solana/wallet-adapter-react'
const { connection } = useConnection()
const accountInfo = await connection.getAccountInfo(timerStatsPDA)
const isExist = accountInfo !== null

I am using connection object from @solana/wallet-adapter-react here, but you can use connection from other npm-packages like @solana/web3.js