John - getAccountIndex()

app.js

function getAccountIndex(acctNumber) {
  for (var i = 0; i < accounts.length; i++) {
    var account = accounts[i];

    if (acctNumber === account.accountNumber) {
      var index = accounts.indexOf(account);
      
      console.log("Found it!");
      console.log("Index: " + accounts.indexOf(account));
      
      return index;
    }
  }
}