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Start your free trialErik Nuber
20,629 PointsUsing a hash symbol in the Balance Method
def addTransaction(description, amount)
@transactions.push(description: description, amount: amount)
end
def balance
balance = 0.0
@transactions.each do |transaction|
balance += transaction[:amount]
end
return balance
end
I am trying to figure out how transaction[:amount] accesses the amount in the array. I would have thought it would be transaction[amount]. I have been back thru the hash course and was unable to find anything other than a few seconds referring to :arg1 being a symbol and that there could be only one versus just arg1. But nothing else mentioned referencing hashes with the hash[:arg1] format.
below is the full code but, don't think it is necessary so I separated out the areas in question above.
class BankAccount
attr_reader :name
def initialize(name)
@name = name
@transactions = []
addTransaction("Beginning Balance", 0)
end
def credit(description, amount)
addTransaction(description, amount)
end
def debit(description, amount)
addTransaction(description, -amount)
end
def addTransaction(description, amount)
@transactions.push(description: description, amount: amount)
end
def balance
balance = 0.0
@transactions.each do |transaction|
balance += transaction[:amount]
end
return balance
end
def to_s
"Name: #{name}, Balance: #{sprintf("%0.2f", balance)}"
end
def printRegister
puts "#{name}'s Bank Account"
puts "-" * 40
puts "Description".ljust(30) + "Amount".rjust(10)
@transactions.each do |trans|
puts trans[:description].ljust(30) + sprintf("%0.2f", trans[:amount]).rjust(10)
end
puts "-" * 40
puts "Balance:".ljust(30) + sprintf("%0.2f", balance).rjust(10)
puts "-" * 40
end
end
bank_account = BankAccount.new("Whomever")
bank_account.credit("Paycheck", 100)
bank_account.debit("Groceries", 40)
puts bank_account.printRegister
1 Answer
PoJung Chen
5,856 PointsThis is because we push hash key with symbol by
@transactions.push(description: description, amount: amount)
This is same as
@transactions.push({:description => description, :amount => amount})
Therefore, we can assess the value through @transaction[":description"]