drills.rb

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9]

puts "Double every value in array."

def double(numbers)
   numbers.each do |num|
    puts num *=2
   end
end

 double(numbers)


puts "or this way..."


for num in numbers
  puts num * 2
end


puts "Max value of array."


def max(numbers)
   puts numbers.max
 end

 max(numbers)


 puts "or this way..."

 puts (1..9).max


puts "Sum of array"

def sum(numbers)
  sum=0
  numbers.each {|num| sum += num}
  puts sum
end

sum(numbers)


puts "or this way..."

def sum(numbers)
puts numbers.inject{|sum, num| sum + num}
end

sum(numbers)


puts "Average of an array."


def average (numbers)
  sum=0
  numbers.each do |num|
  sum += num
  end

  sum/numbers.length.to_f
end

puts average(numbers)


puts "or this way..."

puts numbers.inject {|sum, num| sum + num }.to_f / numbers.size


puts "Return only even numbers from array."

def even(numbers)
  numbers.each do |num|
  if num % 2==0
     puts num
  end
end

even(numbers)


puts "Return only numbers above 6."

def above_six(numbers)
  numbers.each do |num|
    if num > 6
      puts num
    end
  end
end

above_six(numbers)

puts "Now double your even numbers only."
#not sure what I am doing wrong with this one.
#first trys output 2,4,6,8 but should output 4,8,12,16.
#wanted tocall previous method, not sure how after multiple attempts


#def evens_doubled(evens)
  #if even(numbers)=evens

    #???

end