Ruby script to display grades of a student using hashes

class Student
attr_accessor :firstname, :lastname
attr_accessor :lgrade, :agrade
def initialize(fname, lname)
@firstname = fname
@lastname = lname
@grades = Array.new
end
def calcAverage
sum = 0
if @grades.size > 0
@grades.each { |g| sum += g }
@agrade = sum / @grades.size
else
@agrade = 0
end
setLetterGrade
end
def addGrade(score)
if score.is_a?(Integer) || score.is_a?(Float)
@grades.push(score)
calcAverage
end
end
def setLetterGrade
if @agrade >= 90.0
@lgrade = "E"
elsif @agrade >= 80.0
@lgrade = "A"
elsif @agrade >= 70.0
@lgrade = "B"
elsif @agrade >= 60.0
@lgrade = "C"
elsif @agrade >= 50.0
@lgrade = "D"
else
@lgrade = "F"
end
end
end
def findClassAverage(studentsArray)
classSum = 0.0
studentsArray.each { |student| classSum += student.agrade }
if studentsArray.size > 0
return classSum / studentsArray.size
end
return 0
end
student1 = Student.new("John","Smith")
student1.addGrade(80)
student1.addGrade(100.0)
student1.addGrade(54.0)
student2 = Student.new("Mary","Johnson")
student2.addGrade(90.5)
student2.addGrade(90)
student2.addGrade(88.3)
classOfStudents = Array.new
classOfStudents[0] = student1
classOfStudents[1] = student2
classOfStudents.each { |student| puts "Student name: " + student.firstname + " " + student.lastname + " and their average was " + student.agrade.to_s + " " + student.lgrade }
puts "Class Average: " + findClassAverage(classOfStudents).to_s