fibonacci sums ruby

To calculate the sum of Fibonacci numbers in Ruby, you can follow these steps:

1. Define a method called "fibonacci_sum" that takes an integer parameter, "n".
2. Inside the method, initialize three variables: "first" and "second" both set to 0, and "sum" set to 1.
3. Create a loop that iterates "n" times using the "times" method. Inside the loop: a. Calculate the next Fibonacci number by adding "first" and "second" together and store it in a variable called "next_number". b. Update the values of "first", "second", and "sum" accordingly:
   • Set "first" to the current value of "second".
   • Set "second" to the current value of "next_number".
   • Add "next_number" to "sum".
4. After the loop, return the value of "sum".

Here is the code that implements the steps described above:

def fibonacci_sum(n)
  first = 0
  second = 0
  sum = 1

  n.times do
    next_number = first + second
    first = second
    second = next_number
    sum += next_number
  end

  sum
end

You can call this method with the desired value of "n" to calculate the sum of the first "n" Fibonacci numbers.