class Dog
	string name
  	int age
	Dog friend
 
 		void bark()
			print name + " says woof"
 		end bark
endclass

void main()
  Dog fluffy
  // infinite puppies
end main

----------------------------
class Dog
	string name
  	int age
	Dog * friend
	void bark()
		print name + " says woof"
	end bark
endclass


void main()
  Dog fluffy
  fluffy.name = "Muff"
  Dog spot
  spot.name = "Spot"

  spot.friend = *fluffy
  spot.friend.age = 3
  fluffy.age = 3
end main

----------------------------
class Dog
	string name
  	int age
	Dog * friend
endclass

void main()
  Dog fluffy
  fluffy.name = "Muff"
  Dog spot
  spot.name = "Spot"

  spot.friend.age = 3 // ERROR, friend is null
  spot.friend = *fluffy
  spot.friend.age = 3
  fluffy.age = 3
end main

----------------------------
class Dog
	string name
  	int age
 	Dog * friend
endclass

void main()
  Dog fluffy
  fluffy.name = "Muff"
  Dog * spot = new Dog
  spot.name = "Spot"

  fluffy.friend = spot
  spot.friend = new Dog

end main

----------------------------
Dog ozzie
ozzie.age = 10
Dog harriet
dog2.harriet = 7

if (ozzie.age > harriet.age) then
     print ozzie.name  + “ wins!”
     print “lived: “ + ozzie.age
else
	// same code twice
     print harriet.name  + “ wins!”
     print “lived: “ + harriet.age
endif




Dog ozzie
ozzie.age = 10
Dog harriet
dog2.harriet = 7
Dog * winner
if (ozzie.age > harriet.age) then
	winner = *ozzie
else
	winner = *harriet
endif

print winner.name  + “ wins!”
print “lived: “ + winner.age

----------------------------
class Dog
	string name
  	int age
	Dog * friend
	Cat * enemy
endclass

class Cat
	   string name
end class


void main()
  Dog fluffy
  fluffy.name = "Muff"
  Dog spot
  spot.name = "Spot"
  Cat ginger
  ginger.name = "Ginger"
  spot.friend = *fluffy
  spot.enemy = Ginger
  spot.friend.age = 8
  spot.enemy.age = 8 // ERROR, Cat doesn't have age variable
end main

----------------------------
class Dog
	string name
  	int age
 	Dog * friend
endclass

void dogDay(Dog * doggy)
	Dog * newFriend
 newFriend.name = "Mr Friendly"
 doggy.friend = newFriend
 print "it was a big day, " doggy.name + " made a friend
end dogDay

void main()
	Dog spot
 spot.name = "Spot"
 dogDay(spot)
 print spot.friend.name
end main




----------------------------
   
class Course 
	string name
	int credits
	Course * preReq
end class

void main() 
	Course * j2 = new Course
	j2.name = "Java II"
	j2.credits = 4
	Course * j1 =  = new Course
	j1.name = "Java I"
	j1.credits = 4
	Course * fun = new Course
	fun.name = "Fundamentals"
	fun.credits = 3
	Course * basic = new Course
	basic.name = "Computer Basics"
	basic.credits = 3
	j2.preReq = j1
	j1.preReq = fun
	fun.preReq = basic
	
	creditReport(j2)
	creditReport(fun)
end main

void creditReport(Course * aCourse)
	// credits to take this course
	int totalCredits = aCourse.credits
	Course * pre = aCourse.preReq
	// keep adding classes until we have no prereq
	while (pre != null)
	    totalCredits = totalCredits = pre.credits
		// now aCourse is the pre-req of the last class added
		pre = pre.preReq
	end while
end creditReport



// alternative main
void main() 
	Course * j2 = new Course
	j2.name = "Java II"
	j2.credits = 4
	j2.preReq = new Course
	j2.preReq.name = "Java I"
	j2.preReq.credits = 4
	j2.preReq.preReq = new Course
	j2.preReq.preReq.name = "Fundamentals"
	j2.preReq.preReq.credits = 3
	j2.preReq.preReq.preReq = new Course
	j2.preReq.preReq.preReq.name = "Computer Basics"
	j2.preReq.preReq.preReq.credits = 3
	
	creditReport(j2)
	creditReport(j2.preReq.preReq)
end main