Systems Check

list_statistics.rb

scores = [75, 100, 85, 65, 84, 87, 95]

def avg(array)
  total = 0
  array.each do |grade|
    total += grade
  end
  avg = total / array.length
  avg
end

puts avg(scores)


def min(array)
  min = array[0]
  array.each do |grade|
    if grade < min
      min = grade
    end
  end
  min
end

puts min(scores)


def max(array)
  max = array[-1]
  array.each do |grade|
    if grade > max
      max = grade
    end
  end
  max
end

puts max(scores)

Excellent work. These look great. Just a few comments:

Average method

• Might want to return a float instead of an integer
• Don't need the last line, since the return value of avg = total / array.length is the average. You also don't need to assign a variable in that case, since you aren't referencing it later, so your final method might look something like:

def avg(array)
  total = 0

  array.each do |grade|
    total += grade
  end

  total.to_f / array.length
end

Min and max methods

• These look great. Only note I'd make is on naming conventions. I'd probably give your argument a more descriptive name than array, such as numbers or grades. Then in your each loop you can pass it number, num, or grade in the pipes. It's just a bit more descriptive.

Misc.

• This is a personal preference thing, but I like leaving a blank line above and below each loops and most conditionals. I find it guides the eye and makes code easier to read. Ex.:

def max(numbers)
  max = array[-1] # you could also start with array[0] here

  numbers.each do |num|
    if num > max
      max = num
    end
  end

  max
end

Also, in case it's helpful, here's the criteria we use in "grading" these things. The ones towards the bottom will apply to all systems checks:

average method has correct signature
average method calculates average
average method converts to float (OPTIONAL)
average method handles empty list (OPTIONAL)
average method does not modify array
max method has correct signature
max method calculates max
max method does not modify array
max method does not sort the array
max method does not use the Array#max method
min method has correct signature
min method calculates min
min method does not modify array
min method does not sort the array
min method does not use the Array#min method

Proper indentation (2 spaces, no tabs).
Methods and variables have clear, meaningful names.
Method and variable names use underscores, class and module names use camel-case.
No global or instance variables.
Newline included at end of file.
No consecutive (2+) blank lines.
No unnecessary "puts" or "binding.pry" statements

Late for standup without notifying mentor.
Missed standup without notifying mentor.
Absent without notifying mentor.