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

Devin Scheu
Devin Scheu
66,191 Points
Posted by Devin Scheu
Devin Scheu
66,191 Points

Ruby Help

Question: In the BankAccount class, implement a method called balance. The balance method should loop through transactions and calculate the current account balance.

Code:

bank_account.rb 
class BankAccount
  attr_reader :name

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

  def balance
    x = 0
    loop do
      balance += transaction[x]
      x +=1
    end
    return balance
  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

end

3 Answers

Clayton Perszyk
MOD
Clayton Perszyk
Treehouse Moderator 48,723 Points
Clayton Perszyk
Clayton Perszyk
Treehouse Moderator 48,723 Points

Hi Devin

I can spot a few reasons why your code isn't working:

First, you need to declare a variable named balance, and assign it an initial float value:

balance = 0.0

You should be using the each method on the the @transactions array, instead of a loop and iterator. Inside the block for the each method you receive each transaction in turn as a variable (below I've used transaction; each transaction is a hash with a :description and :amount); you can then add the value of each transaction's amount to the balance by using the key, :amount:

@transactions.each do |transaction|
  balance += transaction[:amount]
end

Then you just have to return the balance, like you're already doing.

Devin Scheu
Devin Scheu
66,191 Points
Devin Scheu
Devin Scheu
66,191 Points

This does not seem to be working for me, here is my edited code:

class BankAccount
  attr_reader :name

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

  balance = 0.0

  @transactions.each do |transaction|
    balance += transaction[:amount]
    return balance
  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

end
Clayton Perszyk
Clayton Perszyk
Treehouse Moderator 48,723 Points
Clayton Perszyk
Clayton Perszyk
Treehouse Moderator 48,723 Points

You still want the method definition you had in your original code:

def balance
   /*code for balance*/
end

Also, you want to move return balance outside of the each block and place it before the close of your method definition.

Clayton Perszyk
Clayton Perszyk
Treehouse Moderator 48,723 Points
Clayton Perszyk
Clayton Perszyk
Treehouse Moderator 48,723 Points

Here's what I came up with to pass the challenge:

def balance
  balance = 0.0
  @transactions.each do |transaction|
     balance += transaction[:amount]
  end
  return balance
end
Anterrio Howard
Anterrio Howard
2,625 Points
Anterrio Howard
Anterrio Howard
2,625 Points

This worked:

def balance balance = 0.0 @transactions.each do |transaction| balance += transaction[:amount] end return balance end

Jeremy Hurtt
Jeremy Hurtt
2,940 Points
Jeremy Hurtt
Jeremy Hurtt
2,940 Points

I got this challenge right on the first try, since we had just gone over doing this in the example right before...I was able to remember it easily because I've spent most of the last lesson trying to figure something out about the method this challenge is focusing on...

How does the program understand the variable transaction in this method? Throughout the rest of the code in the program, transaction is never defined or referenced....transactions with an 's' is, as is add_transaction, but not transaction. So when the method iterates through the array, how does the program know what it is adding to the balance with each Did I miss something?