Asp Forum - I need some help plz with my ruby project.

wiz_pendases

10/11/2007 6:07:00 PM

First, i need to extend the student class, and its to be enumerable by
courses. Then, show off the new functionality supported by this
change by writing an expression that returns a list of all of the
grades a student has earned in the courses he or she has completed for
the major.

here is what I got so far...what am i missing
-----------------------------------------------------------------------------------------------------------------
irb

# This class initializes a new student with ID,
# and shows a list of completed courses,
# and also shows a list of grades from completed courses.
class Student

include Enumerable

attr_reader :name, :id

# Initializing the students name and ID.
# Name = Student's name.
# ID = Student's ID.
# Initializing courses to equal a new hash.
def initialize(name, id)
@name = name
@id = id
@courses = {}
end

# Adding a course to the set of those completed.
def add_course(code, name, grade)
@courses[code] = [code, name, grade]
end

# Retrieving the grade for a particular course.
def get_grade(code)
(c=@courses[code]) && c[Grade]
end

# Changing the grade for a course completed.
def set_grade(code, grade)
@courses[code][Grade] = grade
end

# Providing a list of all of the courses completed.
def list_courses
@courses.values
end

def each_grade
@courses.each { |course| yeild course }
end
end

s1 = Student.new("Eric", "00101")
s1.add_course("22c:021", "Computer Science I", "B-")
s1.each_grade.collect { |course| do course[2] }
puts s1
------------------------------------------------------------------------------------------------------------
if you help meh out soon it would be great...thanks and later......

3 Answers

Jeremy Woertink

10/11/2007 7:04:00 PM

well, to start I noticed a few syntax errors, yield is misspelled, and
in the line s1.each_grade.collect { |course| do course[2] } I don't
know what you were trying to do with 'do course[2]' maybe yield
course[2] and your get_grade method has c[Grade] but I don't know what
Grade is, so maybe it should be
def get_grade(code, Grade)
(c=@courses[code]) && c[Grade]
end

maybe that might help a little

~Jeremy

On Oct 11, 11:10 am, wiz_penda...@yahoo.com wrote:
> First, i need to extend the student class, and its to be enumerable by
> courses. Then, show off the new functionality supported by this
> change by writing an expression that returns a list of all of the
> grades a student has earned in the courses he or she has completed for
> the major.
>
> here is what I got so far...what am i missing
> -----------------------------------------------------------------------------------------------------------------
> irb
>
> # This class initializes a new student with ID,
> # and shows a list of completed courses,
> # and also shows a list of grades from completed courses.
> class Student
>
> include Enumerable
>
> attr_reader :name, :id
>
> # Initializing the students name and ID.
> # Name = Student's name.
> # ID = Student's ID.
> # Initializing courses to equal a new hash.
> def initialize(name, id)
> @name = name
> @id = id
> @courses = {}
> end
>
> # Adding a course to the set of those completed.
> def add_course(code, name, grade)
> @courses[code] = [code, name, grade]
> end
>
> # Retrieving the grade for a particular course.
> def get_grade(code)
> (c=@courses[code]) && c[Grade]
> end
>
> # Changing the grade for a course completed.
> def set_grade(code, grade)
> @courses[code][Grade] = grade
> end
>
> # Providing a list of all of the courses completed.
> def list_courses
> @courses.values
> end
>
> def each_grade
> @courses.each { |course| yeild course }
> end
> end
>
> s1 = Student.new("Eric", "00101")
> s1.add_course("22c:021", "Computer Science I", "B-")
> s1.each_grade.collect { |course| do course[2] }
> puts s1
> ------------------------------------------------------------------------------------------------------------
> if you help meh out soon it would be great...thanks and later......

Jeremy Woertink

10/11/2007 7:14:00 PM

oh, and also, take out the collect on s1.each_grade and try just
passing a block to each_grade so
irb(main):009:0> s1.each_grade { |course| puts course[2] }
nil
=> {"22c:021"=>["22c:021", "Computer Science I", "B-"]}

HTH

~Jeremy

On Oct 11, 12:04 pm, "JeremyWoert...@gmail.com"
<JeremyWoert...@gmail.com> wrote:
> well, to start I noticed a few syntax errors, yield is misspelled, and
> in the line s1.each_grade.collect { |course| do course[2] } I don't
> know what you were trying to do with 'do course[2]' maybe yield
> course[2] and your get_grade method has c[Grade] but I don't know what
> Grade is, so maybe it should be
> def get_grade(code, Grade)
> (c=@courses[code]) && c[Grade]
> end
>
> maybe that might help a little
>
> ~Jeremy
>
> On Oct 11, 11:10 am, wiz_penda...@yahoo.com wrote:
>
> > First, i need to extend the student class, and its to be enumerable by
> > courses. Then, show off the new functionality supported by this
> > change by writing an expression that returns a list of all of the
> > grades a student has earned in the courses he or she has completed for
> > the major.
>
> > here is what I got so far...what am i missing
> > -----------------------------------------------------------------------------------------------------------------
> > irb
>
> > # This class initializes a new student with ID,
> > # and shows a list of completed courses,
> > # and also shows a list of grades from completed courses.
> > class Student
>
> > include Enumerable
>
> > attr_reader :name, :id
>
> > # Initializing the students name and ID.
> > # Name = Student's name.
> > # ID = Student's ID.
> > # Initializing courses to equal a new hash.
> > def initialize(name, id)
> > @name = name
> > @id = id
> > @courses = {}
> > end
>
> > # Adding a course to the set of those completed.
> > def add_course(code, name, grade)
> > @courses[code] = [code, name, grade]
> > end
>
> > # Retrieving the grade for a particular course.
> > def get_grade(code)
> > (c=@courses[code]) && c[Grade]
> > end
>
> > # Changing the grade for a course completed.
> > def set_grade(code, grade)
> > @courses[code][Grade] = grade
> > end
>
> > # Providing a list of all of the courses completed.
> > def list_courses
> > @courses.values
> > end
>
> > def each_grade
> > @courses.each { |course| yeild course }
> > end
> > end
>
> > s1 = Student.new("Eric", "00101")
> > s1.add_course("22c:021", "Computer Science I", "B-")
> > s1.each_grade.collect { |course| do course[2] }
> > puts s1
> > ------------------------------------------------------------------------------------------------------------
> > if you help meh out soon it would be great...thanks and later......

ujihisa

10/15/2007 3:37:00 AM

class Student
attr_accessor :courses
def initialize(hash = {})
@name = hash[:name]
@id = hash[:id]
@courses = []

# if you need, write on some validations here.
end
end

class Course
def initialize(hash = {})
@code = hash[:name]
@name = hash[:id]
@grade = hash[:grade]

# if you need, write on some validations here.
end
end

s1 = Student.new :name => "Eric", :code => "00101"
s1.courses << Course.new(:code => "22c:021",
:name => "Computer Science I",
:grade =>"B-")
p s1.courses.map {|c| c[:grade] }

comp.lang.ruby

I need some help plz with my ruby project.

wiz_pendases

Jeremy Woertink

Jeremy Woertink

ujihisa

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