Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Ruby Ruby Objects and Classes Build a Bank Account Class Implement the balance Method

Posted by David Greenstein
David Greenstein
6,734 Points

Why do I have to use [:amount] instead of ["amount"] 

 def balance
    balance = 0
    @transactions.each do |transaction|
      balance += transaction["amount"]
    end
    return balance
  end
bank_account.rb 
class BankAccount
  attr_reader :name

  def initialize(name)
    @name = name
    @transactions = []
    add_transaction("Beginning Balance", 0)
  end

  def debit(description, amount)
    add_transaction(description, -amount)
  end

  def credit(description, amount)
    add_transaction(description, amount)
  end

  def add_transaction(description, amount)
    @transactions.push(description: description, amount: amount)
  end

  def balance
    balance = 0
    @transactions.each do |transaction|
      balance += transaction["amount"]
    end
    return balance
  end


end

1 Answer

Michael Hulet
Michael Hulet
47,913 Points
Michael Hulet
Michael Hulet
47,913 Points

Previously, the value you're looking for was added to the @transactions hash using the symbol :amount as a key, and not the string "amount". Thus, to reference it again, you'll have to use the symbol instead of the string, because doing @transactions[:amount] is entirely different from doing @transaction["amount"], as strings are not symbols and vice versa